This invention relates to modified SARS-CoV-2 coronaviruses, compositions for eliciting an immune response and vaccines for providing protective immunity, prevention and treatment.
All publications herein are incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
An outbreak of a novel coronavirus was identified during mid-December 2019 in the city of Wuhan in central China. A new strain of coronavirus—previously designated as 2019-nCoV (and also previously known as Wuhan Coronavirus), now designated as SARS-CoV-2—was identified. The deadly coronavirus has been declared by the WHO as pandemic. The public health crisis of this virus rapidly grew from claiming the lives of dozens of people and infecting over a thousand as of the end of January 2020, to claiming the lives of over 900,000 people and infecting over 28 million people as of the beginning of September 2020, and to claiming the lives of over 2 million people and infecting over 100 million people as of the last week of January 2021. SARS-CoV-2 viruses are particularly dangerous for the elderly and those with underlying medical conditions such as chronic kidney disease, chronic obstructive pulmonary disease, being immunocompromised from a solid organ transplant, obesity, serious heart conditions, sickle cell disease and type 2 diabetes mellitus. Accordingly, prophylactic and therapeutic treatments are exceedingly and urgently needed.
The following embodiments and aspects thereof are described and illustrated in conjunction with compositions and methods which are meant to be exemplary and illustrative, not limiting in scope.
Various embodiments of the present invention provide for a polynucleotide encoding one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus: wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins, or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide remains the same, or wherein the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 20 amino acid substitutions, additions, or deletions.
In various embodiments, the parent SARS-CoV-2 coronavirus can be a wild-type SARS-CoV-2. In various embodiments, the parent SARS-CoV-2 coronavirus can be a natural isolate SARS-CoV-2. In various embodiments, the parent SARS-CoV-2 coronavirus can be Washington isolate of SARS-CoV-2 coronavirus having a nucleic acid sequence of GenBank accession no. MN985325.1. In various embodiments, the parent SARS-CoV-2 coronavirus can be BetaCoV/Wuhan/IVDC-HB-01/2019 isolate of SARS-CoV-2 coronavirus (SEQ ID NO: 1). In various embodiments, the parent SARS-CoV-2 coronavirus can be a SARS-CoV-2 variant. In various embodiments, the parent SARS-CoV-2 coronavirus can be a SARS-CoV-2 variant selected from the group consisting of U.K. variant, South Africa variant, and Brazil variant.
In various embodiments, the polynucleotide can be recoded by reducing codon-pair bias (CPB) or reducing codon usage bias compared to its parent SARS-CoV-2 coronavirus polynucleotide. In various embodiments, the polynucleotide can be recoded by increasing the number of CpG or UpA di-nucleotides compared to its parent SARS-CoV-2 coronavirus polynucleotide. In various embodiments, each of the recoded one or more viral proteins, or each of the recoded one or more fragments thereof can have a codon pair bias less than, −0.05, less than −0.1, less than −0.2, less than −0.3, or less than −0.4. In various embodiments, the polynucleotide can be CPB deoptimized compared to its parent SARS-CoV-2 coronavirus polynucleotide. In various embodiments, the polynucleotide can be codon deoptimized compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, the codon-deoptimized or CPB deoptimized can be based on frequently used codons or CPB in humans. In various embodiments, the codon-deoptimized or CPB deoptimized can be based on frequently used codons or CPB in a coronavirus. In various embodiments, the codon-deoptimized or CPB deoptimized can be based on frequently used codons or CPB in a SARS-CoV-2 coronavirus. In various embodiments, the codon-deoptimized or CPB deoptimized can be based on frequently used codons or CPB in a wild-type SARS-CoV-2 coronavirus.
In various embodiments, the recoded nucleotide sequence can be selected from RNA-dependent RNA polymerase (RdRP), a fragment of RdRP, a spike protein, a fragment of spike protein, and combinations thereof.
In various embodiments, the polynucleotide can comprise at least one CPB deoptimized region can be selected from bp 11294-12709, bp 14641-15903, bp 21656-22306, bp 22505-23905, and bp 24110-25381 of SEQ ID NO:1 or SEQ ID NO:2.
In various embodiments, the polynucleotide can comprise a recoded spike protein or a fragment of spike protein wherein the furin cleavage site can be eliminated.
In various embodiments, the polynucleotide can comprise the nucleotide sequence of SEQ ID NO:4, nucleotides 1-29,834 of SEQ ID NO:4, SEQ ID NO:7, or nucleotides 1-29,834 of SEQ ID NO:7. In various embodiments, the polynucleotide can further comprise one or more consecutive adenines on the 3′ end.
In various embodiments, the polynucleotide can comprise the nucleotide sequence of SEQ ID NO:3.
Various embodiments of the present invention provide for a bacterial artificial chromosome (BAC) comprising any one of the recoded polynucleotides of the present invention.
Various embodiments of the present invention provide for a vector comprising any one of the recoded polynucleotides of the present invention.
Various embodiments of the present invention provide for a cell comprising any one of the recoded polynucleotides of the present invention, any one of the BAC of the present invention, or any one of the vectors of the present invention. In various embodiments, the cell can be Vero cell or baby hamster kidney (BHK) cell.
Various embodiments of the present invention provide for a polypeptide encoded by any one of the recoded polynucleotides of the present invention.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus comprising any one of the recoded polynucleotides of the present invention.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus comprising any one of the polypeptides of the present invention encoded by any one of the recoded polynucleotides of the present invention.
In various embodiments, wherein expression of one or more viral proteins in any one of the modified SARS-CoV-2 coronavirus of the present invention can be reduced compared to its parent SARS-CoV-2 coronavirus.
In various embodiments, the reduction in the expression of one or more of its viral proteins can be reduced as the result of recoding a region selected from RdRP, spike protein and combinations thereof.
In various embodiments, the modified SARS-CoV-2 coronavirus can comprise a polynucleotide having SEQ ID NO:4, or nucleotides 1-29,834 of SEQ ID NO:4, or nucleotides 1-29,834 of SEQ ID NO:4 and one or more consecutive adenines on the 3′ end.
In various embodiments, the modified SARS-CoV-2 coronavirus can comprise a polypeptide encoded by a polynucleotide having SEQ ID NO:4, or nucleotides 1-29,834 of SEQ ID NO:4, or nucleotides 1-29,834 of SEQ ID NO:4 and one or more consecutive adenines on the 3′ end.
Various embodiments of the present invention provide for a vaccine composition for inducing a protective an immune response in a subject, comprising: any one of the modified SARS-CoV-2 coronavirus of the present invention. In various embodiments, the vaccine composition can further comprise a pharmaceutically acceptable carrier or excipient.
Various embodiments of the present invention provide for an immune composition for eliciting an immune response in a subject, comprising: any one of the modified SARS-CoV-2 coronavirus of the present invention. In various embodiments, the immune composition can further comprise a pharmaceutically acceptable carrier or excipient.
Various embodiments of the present invention provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a dose of: any one of the modified SARS-CoV-2 coronaviruses of the present invention, or any one of the vaccine compositions the present invention, or any one of the immune compositions of the present invention.
Various embodiments of the present invention provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a prime dose of any one of the modified SARS-CoV-2 coronaviruses of the present invention, or any one of the vaccine compositions of the present invention, or any one of the immune compositions of the present invention; and administering to the subject one or more boost doses of any one of the modified SARS-CoV-2 coronaviruses of the present invention, or any one of the vaccine compositions of the present invention, or any one of the immune compositions of the present invention.
In various embodiments, the immune response is a protective immune response.
In various embodiments, the dose can be a prophylactically effective or therapeutically effective dose. In various embodiments, the dose can be about 104-106 PFU, or the prime dose can be about 104-106 PFU and the one or more boost dose can be about 104-106 PFU.
In various embodiments, administering can be via a nasal route. In various embodiments, administering can be via nasal drop. In various embodiments, administering can be via nasal spray.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention for use in eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention for use in eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19, wherein the use comprises a prime dose of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention, and one or more boost doses of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention.
Various embodiments of the present invention provide for a use of modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention in the manufacture of a medicament for eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19.
Various embodiments of the present invention provide for a use of modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention in the manufacture of a medicament for use in eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19, wherein the medicament comprises a prime dose of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention, and one or more boost doses of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention.
The modified SARS-CoV-2 coronavirus of the present invention is any one of the modified SARS-CoV-2 coronavirus discussed herein. The vaccine composition of the present invention is any one of the vaccine compositions discussed herein. The immune composition of the present invention is any one of the immune compositions discussed herein. In various embodiments, the immune response is a protective immune response.
Various embodiments of the present invention provide for a method of making a modified SARS-CoV-2 coronavirus, comprising: obtaining a nucleotide sequence encoding one or more proteins of a parent SARS-CoV-2 coronavirus or one or more fragments thereof, recoding the nucleotide sequence to reduce protein expression of the one or more proteins, or the one or more fragments thereof, and substituting a nucleic acid having the recoded nucleotide sequence into the parent SARS-CoV-2 coronavirus genome to make the modified SARS-CoV-2 coronavirus genome, wherein expression of the recoded nucleotide sequence is reduced compared to the parent virus.
In various embodiments, the parent SARS-CoV-2 coronavirus sequence can be a wild-type (wt) viral nucleic acid, or a natural isolate.
In various embodiments, the modified SARS-CoV-2 coronavirus is any one of the modified SARS-CoV-2 coronavirus of the present invention.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, various features of embodiments of the invention.
Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
All references cited herein are incorporated by reference in their entirety as though fully set forth. Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Singleton et al., Dictionary of Microbiology and Molecular Biology 3rd ed., Revised, J. Wiley & Sons (New York, N.Y. 2006); March, Advanced Organic Chemistry Reactions, Mechanisms and Structure 7th ed., J. Wiley & Sons (New York, N.Y. 2013); and Sambrook and Russel, Molecular Cloning: A Laboratory Manual 4th ed., Cold Spring Harbor Laboratory Press (Cold Spring Harbor, N.Y. 2012), provide one skilled in the art with a general guide to many of the terms used in the present application.
One skilled in the art will recognize many methods and materials similar or equivalent to those described herein, which could be used in the practice of the present invention. Indeed, the present invention is in no way limited to the methods and materials described. For purposes of the present invention, the following terms are defined below.
As used herein the term “about” when used in connection with a referenced numeric indication means the referenced numeric indication plus or minus up to 5% of that referenced numeric indication, unless otherwise specifically provided for herein. For example, the language “about 50%” covers the range of 45% to 55%. In various embodiments, the term “about” when used in connection with a referenced numeric indication can mean the referenced numeric indication plus or minus up to 4%, 3%, 2%, 1%, or 0.5% of that referenced numeric indication, if specifically provided for in the claims.
“Parent virus” as used herein refer to a reference virus to which a recoded nucleotide sequence is compared for encoding the same or similar amino acid sequence.
“Wuhan coronavirus” and “SARS-CoV-2” and “2019-nCoV” as used herein are interchangeable, and refer to a coronavirus that has a wild-type sequence, natural isolate sequence, or mutant forms of the wild-type sequence or natural isolate sequence that causes COVID-19. Mutant forms arise naturally through the virus' replication cycles, or through genetic engineering.
“SARS-CoV-2 variant” as used herein refers to a mutant form of SARS-CoV-2 that has developed naturally through the virus' replication cycles as it replicates in and/or transmits between hosts such as humans. Examples of SARS-CoV-2 variants include but are not limited to U.K. variant (also known as 201/501Y.V1, VOC 202012/01, or B.1.1.7), South African variant (also known as 20H/501Y.V2 or B.1.351), and Brazil variant (also known as P.1).
“Natural isolate” as used herein with reference to SARS-CoV-2 refers to a virus such as SARS-CoV-2 that has been isolated from a host (e.g., human, bat, feline, pig, or any other host) or natural reservoir. The sequence of the natural isolate can be identical or have mutations that arose naturally through the virus' replication cycles as it replicates in and/or transmits between hosts, for example, humans.
“Wuhan coronavirus isolate” as used herein refers to a wild-type isolate of SARS-CoV-2 that has Accession ID: EPI_ISL_402119, submitted Jan. 10, 2020, and also referred to as BetaCoV/Wuhan/IVDC-HB-01/2019, SEQ ID NO: 1, which is herein incorporated by reference as though fully set forth in its entirety.
“Washington coronavirus isolate” as used herein refers to a wild-type isolate of SARS-CoV-2 that has GenBank accession no. MN985325.1 as of Jul. 5, 2020, which is herein incorporated by reference as though fully set forth in its entirety.
“Frequently used codons” or “codon usage bias” as used herein refer to differences in the frequency of occurrence of synonymous codons in coding DNA for a particular species, for example, human, coronavirus, or SARS-CoV-2.
“Codon pair bias” as used herein refers to synonymous codon pairs that are used more or less frequently than statistically predicted in a particular species, for example, human, coronavirus, or SARS-CoV-2.
A “subject” as used herein means any animal or artificially modified animal. Animals include, but are not limited to, humans, non-human primates, cows, horses, sheep, pigs, dogs, cats, rabbits, ferrets, rodents such as mice, rats and guinea pigs, bats, snakes, and birds. Artificially modified animals include, but are not limited to, SCID mice with human immune systems. In a preferred embodiment, the subject is a human.
A “viral host” means any animal or artificially modified animal that a virus can infect. Animals include, but are not limited to, humans, non-human primates, cows, horses, sheep, pigs, dogs, cats, rabbits, ferrets, rodents such as mice, rats and guinea pigs, and birds. Artificially modified animals include, but are not limited to, SCID mice with human immune systems. In various embodiments, the viral host is a mammal. In various embodiments, the viral host is a primate. In various embodiments, the viral host is human. Embodiments of birds are domesticated poultry species, including, but not limited to, chickens, turkeys, ducks, and geese.
A “prophylactically effective dose” is any amount of a vaccine or virus composition that, when administered to a subject prone to viral infection or prone to affliction with a virus-associated disorder, induces in the subject an immune response that protects the subject from becoming infected by the virus or afflicted with the disorder. “Protecting” the subject means either reducing the likelihood of the subject's becoming infected with the virus, or lessening the likelihood of the disorder's onset in the subject, by at least two-fold, preferably at least ten-fold, 25-fold, 50-fold, or 100 fold. For example, if a subject has a 1% chance of becoming infected with a virus, a two-fold reduction in the likelihood of the subject becoming infected with the virus would result in the subject having a 0.5% chance of becoming infected with the virus.
As used herein, a “therapeutically effective dose” is any amount of a vaccine or virus composition that, when administered to a subject afflicted with a disorder against which the vaccine is effective, induces in the subject an immune response that causes the subject to experience a reduction, remission or regression of the disorder and/or its symptoms. In preferred embodiments, recurrence of the disorder and/or its symptoms is prevented. In other preferred embodiments, the subject is cured of the disorder and/or its symptoms.
Certain embodiments of any of the instant immunization and therapeutic methods further comprise administering to the subject at least one adjuvant. An “adjuvant” shall mean any agent suitable for enhancing the immunogenicity of an antigen and boosting an immune response in a subject. Numerous adjuvants, including particulate adjuvants, suitable for use with both protein- and nucleic acid-based vaccines, and methods of combining adjuvants with antigens, are well known to those skilled in the art. Suitable adjuvants for nucleic acid based vaccines include, but are not limited to, Quil A, imiquimod, resiquimod, and interleukin-12 delivered in purified protein or nucleic acid form. Adjuvants suitable for use with protein immunization include, but are not limited to, alum, Freund's incomplete adjuvant (FIA), saponin, Quil A, and QS-21.
Described herein are SARS-CoV-2 viruses wherein its genes have been recoded, for example, codon deoptimized or codon pair bias deoptimized. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus; however, the nucleotide sequences have been recoded. Recoding of the nucleotide sequence in accordance with the present invention results in reduced protein expression, attenuation or both. These recoded SARS-CoV-2 viruses are useful as vaccines, and particularly, for use as live-attenuated vaccines.
We generated a synthetic highly attenuated live vaccine candidate, COVI-VAC (also referred to as CDX-005; e.g., SEQ ID NO:4)) from wt SARS-CoV-2. While not wishing to be bound by any particular theory, we believe that the most likely mechanism for the attenuation is slowed translation, through errors in translation leading to misfolded proteins, changes in RNA secondary structure, or altered regulatory signals may all contribute to reduced protein production. Whatever the mechanism, the attenuated COVI-VAC virus presents every viral antigen in its wt form, providing the potential for a broad immune response and making it likely to retain efficacy even if there is genetic drift in the target strain. COVI-VAC is expected to be highly resistant to reversion to pathogenicity since hundreds of silent (synonymous) mutations contribute to the phenotype. Our tests of reversion indicate that the vaccine is stable as assessed by bulk sequencing of late passage virus and evaluation of potential changes in the furin cleavage site.
Our hamster studies demonstrate that COVI-VAC is safe in these animals. It is highly attenuated, inducing lower total viral loads in the lungs and olfactory bulb and completely abrogating it in the brain and inducing lower live viral loads in the lung of animals inoculated with COVI-VAC than those with wt WA1. Unlike wt virus, COVI-VAC did not induce weight loss or significant lung pathology in inoculated hamsters.
The hamster studies also suggest that COVI-VAC effectively protect against SARS CoV-2. Assessment of Abs titers demonstrate that it is as effective as wt virus in inducing serum IgG and neutralizing Abs. It is protective against wt challenge; inoculation with COVI-VAC leads to lower lung viral titers and complete protection against virus in the brain. Hamsters inoculated with COVI-VAC also do not exhibit the weight loss observed in vehicle inoculated animals. Moreover, there is no evidence of disease enhancement.
Together our data indicates that COVI-VAC is a part of an important new class of live attenuated vaccines currently being developed for use in animals and humans. It presents all viral antigens similar to their native amino acid sequence, can be administered intranasally, is safe and effective in small animal models with a single dose, is resistant to reversion, and can be grown to high titers at a permissive temperature. Clinical trials are currently underway to test its safety and efficacy in humans.
To construct the deoptimized CDX-005 (e.g., SEQ ID NO:4) and CDX-007 (e.g., SEQ ID NO:7) live attenuated vaccine candidates, first the genome of the wild-type WA1 donor virus was parsed in silico into 19 overlapping fragments. Each fragment shares approximately 200 bp of sequence overlap with each adjacent fragment. F1-F19 were generated from cDNA of wild-type WA1 virus RNA by RT-PCR. The fragments were sequence confirmed by Sanger sequencing. We then exchanged Fragment 16 of the WT WA1 virus for fragment 16 that had the deoptimized spike gene sequence to generate the cDNA genome of CDX-005. Similarly, we exchanged Fragment 14 of the WT WA1 virus for fragment 14 that had the deoptimized spike gene sequence to generate the cDNA genome of CDX-007.
In various embodiments, the molecular parsing of a target Parent virus into small fragments each with about 50 to 300 bp overlaps via RT-PCR and the exchange of any of these fragments is a process that can be used to construct the cDNA genome or genome fragment of any codon-, or codon-pair-deoptimized virus. This cDNA genome with the deoptimized cassette can then be used to recover a deoptimized virus via reverse genetics.
For CDX-005 and CDX-007, w identified one notable difference in the sequence of our WA1 donor virus (Vero cell passage 6) compared to the published WA1 sequence (Vero cell passage 4). During the two additional WA1 virus passages on Vero E6 cells at Codagenix of the WA1 virus received from BEI Resources, a 36 nt deletion occurred in the Spike gene (genome position 23594-23629). The deletion encompasses the 12 amino acids TNSPRRARSVAS (SEQ ID NO:8) that include the polybasic furin cleavage site. The furin cleavage site in SARS-CoV2 Spike has been proposed as a potential driver of the highly pathogenic phenotype of SARS-CoV2 in the human host. While not wishing to be bound by any particular theory, we believe that absence of the furin cleavage is beneficial to the SARS-CoV-2 virus growth in vitro in Vero cells, and that the deletion evolved during passaging in Vero cell culture. We further believe that the absence of the furin cleavage site may contribute to attenuation in the human host of a SARS-CoV-2 virus carrying such mutation. We therefore decided to incorporate the furin cleavage site deletion that was derived into our vaccine candidates CDX-005, and CDX-007. The furin cleavage site deletion is located in assembly fragment F15.
The present invention is based, at least in part, on the foregoing and on the further information as described herein.
In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but with up to about 20 amino acid deletion(s), substitution(s), or addition(s). However, the nucleotide sequences have been recoded, which results in reduced protein expression, attenuation or both. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but with up to 10 amino acid deletions, substitutions, or additions; however, the nucleotide sequences have been recoded, which results in reduced protein expression, attenuation or both. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but between 1-5 amino acid deletion, substitution, or addition. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but between 6-10 amino acid deletion, substitution, or addition. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but between 11-15 amino acid deletion, substitution, or addition. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but between 16-20 amino acid deletion, substitution, or addition. Again, however, the nucleotide sequences have been recoded, which results in reduced protein expression, attenuation or both. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but 12 amino acid deletions, substitutions, or additions; however, the nucleotide sequences have been recoded, which results in reduced protein expression, attenuation or both. In various embodiments, the amino acid deletion, substitution, or addition results from nucleic acid deletion(s), substitution(s) or addition(s) before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but with a 12 amino acid deletion. In various embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but with a 1-5 amino acid deletion, or a 6-10 amino acid deletion, or a 11-15 amino acid deletion, or a 16-20 amino acid deletion. In various embodiments, the amino acid deletion is in the Spike protein that eliminates the furin cleavage site. In various particular embodiments, the viral proteins of SARS-CoV-2 viruses of the present invention have the same amino acid sequences as its parent SARS-CoV-2 virus but with a 12 amino acid deletion that results in the elimination of the furin cleavage site on the Spike protein. In various embodiments, the amino acid deletion, substitution, or addition results from nucleic acid deletion(s), substitution(s) or addition(s) before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
In various embodiments, the nucleic acid encoding the RNA-dependent RNA polymerase (RdRP) protein of the SARS-CoV-2 virus is recoded. In other embodiments, the nucleic acid encoding the spike protein (also known as S gene) of the SARS-CoV-2 virus is recoded. In still other embodiments, both the RdRP and the spike proteins of the SARS-CoV-2 virus are recoded. In various embodiments, the recoded spike protein comprises a deletion of nucleotides that eliminates the furin cleavage site; for example, a 36 nucleotide sequence having SEQ ID NO:5.
The recoding of RdRP and/or spike protein encoding sequences of the attenuated viruses of the invention have been made or can be made by one of skill in the art in light of disclosure discussed herein. According to various embodiments of the invention, nucleotide substitutions are engineered in multiple locations in the RdRP and/or spike protein coding sequence, wherein the substitutions introduce a plurality of synonymous codons into the genome. In certain embodiments, the synonymous codon substitutions alter codon bias, codon pair bias, the density of infrequent codons or infrequently occurring codon pairs, RNA secondary structure, CG and/or TA (or UA) dinucleotide content, C+G content, translation frameshift sites, translation pause sites, the presence or absence of microRNA recognition sequences or any combination thereof, in the genome. The codon substitutions may be engineered in multiple locations distributed throughout the RdRP and/or spike protein coding sequence, or in the multiple locations restricted to a portion of the RdRP and/or spike protein coding sequence. Because of the large number of defects (i.e., nucleotide substitutions) involved, the invention allows for production of stably attenuated viruses and live vaccines.
As discussed further below, in some embodiments, a virus coding sequence is recoded by substituting one or more codon with synonymous codons used less frequently in the SARS-CoV-2 coronavirus host (e.g., humans, snakes, bats). In some embodiments, a virus coding sequence is recoded by substituting one or more codons with synonymous codons used less frequently in a coronavirus; for example, the SARS-CoV-2 coronavirus. In certain embodiments, the number of codons substituted with synonymous codons is at least 5. In some embodiments, at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 250, 300, 350, 400, 450, or 500 codons are substituted with synonymous codons less frequently used in the host. In certain embodiments, the modified sequence comprises at least 20 codons substituted with synonymous codons less frequently used. In certain embodiments, the modified sequence comprises at least 50 codons substituted with synonymous codons less frequently used. In certain embodiments, the modified sequence comprises at least 100 codons substituted with synonymous codons less frequently used. In certain embodiments, the modified sequence comprises at least 250 codons substituted with synonymous codons less frequently used. In certain embodiments, the modified sequence comprises at least 500 codons substituted with synonymous codons less frequently used.
For example, for the recoded spike protein, the number of codons substituted with synonymous codons less frequently used in the host is at least 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, or 500 codons.
For example, for the recoded RdRP protein, the number of codons substituted with synonymous codons less frequently used in the host is at least 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, or 300 codons.
In some embodiments, the substitution of synonymous codons is with those that are less frequent in the viral host; for example, human. Other examples of viral hosts include but are not limited to those noted above. In some embodiments, the substitution of synonymous codons is with those that are less frequent in the virus itself, for example, the SARS-CoV-2 coronavirus.
In embodiments wherein the modified sequence comprises an increased number of CpG or UpA di-nucleotides compared to a corresponding sequence on the parent virus, the increase is of about 15-55 CpG or UpA di-nucleotides compared the corresponding sequence. In various embodiments, increase is of about 15, 20, 25, 30, 35, 40, 45, or 55 CpG or UpA di-nucleotides compared the corresponding sequence. In some embodiments, the increased number of CpG or UpA di-nucleotides compared to a corresponding sequence is about 10-75, 15-25, 25-50, or 50-75 CpG or UpA di-nucleotides compared the corresponding sequence.
In some embodiments, virus codon pairs are recoded to reduce (i.e., lower the value of) codon-pair bias. In certain embodiments, codon-pair bias is reduced by identifying a codon pair in an RdRP and/or spike coding sequence having a codon-pair score that can be reduced and reducing the codon-pair bias by substituting the codon pair with a codon pair that has a lower codon-pair score. In some embodiments, this substitution of codon pairs takes the form of rearranging existing codons of a sequence. In some such embodiments, a subset of codon pairs is substituted by rearranging a subset of synonymous codons. In other embodiments, codon pairs are substituted by maximizing the number of rearranged synonymous codons. It is noted that while rearrangement of codons leads to codon-pair bias that is reduced (made more negative) for the virus coding sequence overall, and the rearrangement results in a decreased CPS at many locations, there may be accompanying CPS increases at other locations, but on average, the codon pair scores, and thus the CPB of the modified sequence, is reduced. In some embodiments, recoding of codons or codon-pairs can take into account altering the G+C content of the RdRP and/or spike coding sequence. In some embodiments, recoding of codons or codon-pairs can take into account altering the frequency of CG and/or TA dinucleotides in the RdRP and/or spike coding sequence.
In certain embodiments, the recoded RdRP and/or spike protein-encoding sequence has a codon pair bias less than −0.1, or less than −0.2, or less than −0.3, or less than −0.4. In some embodiments, the recoded RdRP and/or spike protein-encoding sequence has a codon pair bias less than −0.05, or less than −0.06, or less than −0.07, or less than −0.08, or less than −0.09, or less than −0.1, or less than −0.11, or less than −0.12, or less than −0.13, or less than −0.14, or less than −0.15, or less than −0.16, or less than −0.17, or less than −0.18, or less than −0.19, or less than −0.2, or less than −0.25, or less than −0.3, or less than −0.35, or less than −0.4, or less than −0.45, or less than −0.5.
In certain embodiments, the codon pair bias of the recoded RdRP and/or spike protein encoding sequence is reduced by at least 0.1, or at least 0.2, or at least 0.3, or at least 0.4, compared to the parent RdRP and/or spike protein encoding sequence from which it is derived (e.g., the parent sequence RdRP and/or spike protein encoding sequence, the wild-type sequence RdRP and/or spike protein encoding sequence). In certain embodiments, rearrangement of synonymous codons of the RdRP and/or spike protein-encoding sequence provides a codon-pair bias reduction of at least 0.1, or at least 0.2, or at least 0.3, or at least 0.4, compared to the parent RdRP and/or spike protein encoding sequence from which it is derived. In certain embodiments, the codon pair bias of the recoded the RdRP and/or spike protein-encoding sequence is reduced by at least 0.05, or at least 0.06, or at least 0.07, or at least 0.08, or at least 0.09, or at least 0.1, or at least 0.11, or at least 0.12, or at least 0.13, or at least 0.14, or at least 0.15, or at least 0.16, or at least 0.17, or at least 0.18, or at least 0.19, or at least 0.2, or at least 0.25, or at least 0.3, or at least 0.35, or at least 0.4, or at least 0.45, or at least 0.5, compared to the corresponding sequence on the parent virus. In certain embodiments, it is in comparison corresponding sequence from which the calculation is to be made; for example, the corresponding sequence of a wild-type virus (e.g., RdRP and/or spike protein-encoding sequence on wild-type virus).
Usually, these substitutions and alterations are made and reduce expression of the encoded virus proteins without altering the amino acid sequence of the encoded protein. In certain embodiments, the invention also includes alterations in the RdRP and/or spike coding sequence that result in substitution of non-synonymous codons and amino acid substitutions in the encoded protein, which may or may not be conservative. In some embodiments, these substitutions and alterations further include substitutions or alterations that results in amino acid deletions, additions, substitutions. For example, the spike protein can be recoded with a 36 nucleotide deletion that results in the elimination of the furin cleavage site.
Most amino acids are encoded by more than one codon. See the genetic code in Table 1. For instance, alanine is encoded by GCU, GCC, GCA, and GCG. Three amino acids (Leu, Ser, and Arg) are encoded by six different codons, while only Trp and Met have unique codons. “Synonymous” codons are codons that encode the same amino acid. Thus, for example, CUU, CUC, CUA, CUG, UUA, and UUG are synonymous codons that code for Leu. Synonymous codons are not used with equal frequency. In general, the most frequently used codons in a particular organism are those for which the cognate tRNA is abundant, and the use of these codons enhances the rate and/or accuracy of protein translation. Conversely, tRNAs for the rarely used codons are found at relatively low levels, and the use of rare codons is thought to reduce translation rate and/or accuracy.
a The first nucleotide in each codon encoding a particular amino acid is shown in the left-most column; the sec ond nucleotide is shown in the top row; and the third nucleotide is shown in the right-most column.
As used herein, a “rare” codon is one of at least two synonymous codons encoding a particular amino acid that is present in an mRNA at a significantly lower frequency than the most frequently used codon for that amino acid. Thus, the rare codon may be present at about a 2-fold lower frequency than the most frequently used codon. Preferably, the rare codon is present at least a 3-fold, more preferably at least a 5-fold, lower frequency than the most frequently used codon for the amino acid. Conversely, a “frequent” codon is one of at least two synonymous codons encoding a particular amino acid that is present in an mRNA at a significantly higher frequency than the least frequently used codon for that amino acid. The frequent codon may be present at about a 2-fold, preferably at least a 3-fold, more preferably at least a 5-fold, higher frequency than the least frequently used codon for the amino acid. For example, human genes use the leucine codon CTG 40% of the time, but use the synonymous CTA only 7% of the time (see Table 2). Thus, CTG is a frequent codon, whereas CTA is a rare codon. Roughly consistent with these frequencies of usage, there are 6 copies in the genome for the gene for the tRNA recognizing CTG, whereas there are only 2 copies of the gene for the tRNA recognizing CTA. Similarly, human genes use the frequent codons TCT and TCC for serine 18% and 22% of the time, respectively, but the rare codon TCG only 5% of the time. TCT and TCC are read, via wobble, by the same tRNA, which has 10 copies of its gene in the genome, while TCG is read by a tRNA with only 4 copies. It is well known that those mRNAs that are very actively translated are strongly biased to use only the most frequent codons. This includes genes for ribosomal proteins and glycolytic enzymes. On the other hand, mRNAs for relatively non-abundant proteins may use the rare codons.
The propensity for highly expressed genes to use frequent codons is called “codon bias.” A gene for a ribosomal protein might use only the 20 to 25 most frequent of the 61 codons, and have a high codon bias (a codon bias close to 1), while a poorly expressed gene might use all 61 codons, and have little or no codon bias (a codon bias close to 0). It is thought that the frequently used codons are codons where larger amounts of the cognate tRNA are expressed, and that use of these codons allows translation to proceed more rapidly, or more accurately, or both.
In addition, a given organism has a preference for the nearest codon neighbor of a given codon A, referred to a bias in codon pair utilization. A change of codon pair bias, without changing the existing codons, can influence the rate of protein synthesis and production of a protein.
Codon pair bias may be illustrated by considering the amino acid pair Ala-Glu, which can be encoded by 8 different codon pairs. If no factors other than the frequency of each individual codon (as shown in Table 2) are responsible for the frequency of the codon pair, the expected frequency of each of the 8 encodings can be calculated by multiplying the frequencies of the two relevant codons. For example, by this calculation the codon pair GCA-GAA would be expected to occur at a frequency of 0.097 out of all Ala-Glu coding pairs (0.23×0.42; based on the frequencies in Table 2). In order to relate the expected (hypothetical) frequency of each codon pair to the actually observed frequency in the human genome the Consensus CDS (CCDS) database of consistently annotated human coding regions, containing a total of 14,795 human genes, was used. This set of genes is the most comprehensive representation of human coding sequences. Using this set of genes, the frequencies of codon usage were re-calculated by dividing the number of occurrences of a codon by the number of all synonymous codons coding for the same amino acid. As expected the frequencies correlated closely with previously published ones such as the ones given in Table 2. Slight frequency variations are possibly due to an oversampling effect in the data provided by the codon usage database at Kazusa DNA Research Institute (www.kazusa.or.jp/codon/codon.html) where 84949 human coding sequences were included in the calculation (far more than the actual number of human genes). The codon frequencies thus calculated were then used to calculate the expected codon-pair frequencies by first multiplying the frequencies of the two relevant codons with each other (see Table 3 expected frequency), and then multiplying this result with the observed frequency (in the entire CCDS data set) with which the amino acid pair encoded by the codon pair in question occurs. In the example of codon pair GCA-GAA, this second calculation gives an expected frequency of 0.098 (compared to 0.097 in the first calculation using the Kazusa dataset). Finally, the actual codon pair frequencies as observed in a set of 14,795 human genes was determined by counting the total number of occurrences of each codon pair in the set and dividing it by the number of all synonymous coding pairs in the set coding for the same amino acid pair (Table 3; observed frequency). Frequency and observed/expected values for the complete set of 3721 (612) codon pairs, based on the set of 14,795 human genes, are provided herewith as Table 3.
If the ratio of observed frequency/expected frequency of the codon pair is greater than one the codon pair is said to be overrepresented. If the ratio is smaller than one, it is said to be underrepresented. In the example, the codon pair GCA-GAA is overrepresented 1.65 fold while the coding pair GCC-GAA is more than 5-fold underrepresented.
Many other codon pairs show very strong bias; some pairs are under-represented, while other pairs are over-represented. For instance, the codon pairs GCCGAA (AlaGlu) and GATCTG (AspLeu) are three- to six-fold under-represented (the preferred pairs being GCAGAG and GACCTG, respectively), while the codon pairs GCCAAG (AlaLys) and AATGAA (AsnGlu) are about two-fold over-represented. It is noteworthy that codon pair bias has nothing to do with the frequency of pairs of amino acids, nor with the frequency of individual codons. For instance, the under-represented pair GATCTG (AspLeu) happens to use the most frequent Leu codon, (CTG).
As discussed more fully below, codon pair bias takes into account the score for each codon pair in a coding sequence averaged over the entire length of the coding sequence. According to the invention, codon pair bias is determined by
Accordingly, similar codon pair bias for a coding sequence can be obtained, for example, by minimized codon pair scores over a subsequence or moderately diminished codon pair scores over the full length of the coding sequence.
Every individual codon pair of the possible 3721 non-“STOP” containing codon pairs (e.g., GTT-GCT) carries an assigned “codon pair score,” or “CPS” that is specific for a given “training set” of genes. The CPS of a given codon pair is defined as the log ratio of the observed number of occurrences over the number that would have been expected in this set of genes (in this example the human genome). Determining the actual number of occurrences of a particular codon pair (or in other words the likelihood of a particular amino acid pair being encoded by a particular codon pair) is simply a matter of counting the actual number of occurrences of a codon pair in a particular set of coding sequences. Determining the expected number, however, requires additional calculations. The expected number is calculated so as to be independent of both amino acid frequency and codon bias similarly to Gutman and Hatfield. That is, the expected frequency is calculated based on the relative proportion of the number of times an amino acid is encoded by a specific codon. A positive CPS value signifies that the given codon pair is statistically over-represented, and a negative CPS indicates the pair is statistically under-represented in the human genome.
To perform these calculations within the human context, the most recent Consensus CDS (CCDS) database of consistently annotated human coding regions, containing a total of 14,795 genes, was used. This data set provided codon and codon pair, and thus amino acid and amino-acid pair frequencies on a genomic scale.
The paradigm of Federov et al. (2002), was used to further enhanced the approach of Gutman and Hatfield (1989). This allowed calculation of the expected frequency of a given codon pair independent of codon frequency and non-random associations of neighboring codons encoding a particular amino acid pair. The detailed equations used to calculate CPB are disclosed in WO 2008/121992 and WO 2011/044561, which are incorporated by reference.
In the calculation, Pij is a codon pair occurring with a frequency of NO(Pij) in its synonymous group. Ci and Cj are the two codons comprising Pij, occurring with frequencies F(Ci) and F(Cj) in their synonymous groups respectively. More explicitly, F(Ci) is the frequency that corresponding amino acid Xi is coded by codon Ci throughout all coding regions and F(Ci)═NO(Cj)/NO(Xi), where NO(Ci) and NO(Xi) are the observed number of occurrences of codon Ci and amino acid Xi respectively. F(Cj) is calculated accordingly. Further, NO(Xij) is the number of occurrences of amino acid pair Xij throughout all coding regions. The codon pair bias score S(Pij) of Pij was calculated as the log-odds ratio of the observed frequency NO(Pij) over the expected number of occurrences of Ne(Pij).
Using the formula above, it was then determined whether individual codon pairs in individual coding sequences are over- or under-represented when compared to the corresponding genomic Ne(Pij) values that were calculated by using the entire human CCDS data set. This calculation resulted in positive S(Pij) score values for over-represented and negative values for under-represented codon pairs in the human coding regions.
The “combined” codon pair bias of an individual coding sequence was calculated by averaging all codon pair scores according to the following formula:
The codon pair bias of an entire coding region is thus calculated by adding all of the individual codon pair scores comprising the region and dividing this sum by the length of the coding sequence.
An algorithm was developed to quantify codon pair bias. Every possible individual codon pair was given a “codon pair score”, or “CPS”. CPS is defined as the natural log of the ratio of the observed over the expected number of occurrences of each codon pair over all human coding regions, where humans represent the host species of the instant vaccine virus to be recoded.
Although the calculation of the observed occurrences of a particular codon pair is straightforward (the actual count within the gene set), the expected number of occurrences of a codon pair requires additional calculation. We calculate this expected number to be independent both of amino acid frequency and of codon bias, similar to Gutman and Hatfield. That is, the expected frequency is calculated based on the relative proportion of the number of times an amino acid is encoded by a specific codon. A positive CPS value signifies that the given codon pair is statistically over-represented, and a negative CPS indicates the pair is statistically under-represented in the human genome.
Using these calculated CPSs, any coding region can then be rated as using over- or under-represented codon pairs by taking the average of the codon pair scores, thus giving a Codon Pair Bias (CPB) for the entire gene.
The CPB has been calculated for all annotated human genes using the equations shown and plotted. Each point in the graph corresponds to the CPB of a single human gene. The peak of the distribution has a positive codon pair bias of 0.07, which is the mean score for all annotated human genes. Also, there are very few genes with a negative codon pair bias. Equations established to define and calculate CPB were then used to manipulate this bias.
Recoding of protein-encoding sequences may be performed with or without the aid of a computer, using, for example, a gradient descent, or simulated annealing, or other minimization routine. An example of the procedure that rearranges codons present in a starting sequence can be represented by the following steps:
Attenuation of viruses by reducing codon pair bias is disclosed in WO 2008/121992 and WO 2011/044561, which are incorporated by reference as though fully set forth.
Methods of obtaining full-length SARS-CoV-2 genome sequence or codon pair deoptimized sequences embedded in a wild-type SARS-CoV-2 genome sequence (or its mutant forms of the wild-type sequence that causes COVID-19) can include for example, constructing an infectious cDNA clone, using BAC vector, using an overlap extension PCR strategy, or long PCR-based fusion strategy.
Various embodiments of the present invention provide for a polynucleotide encoding one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus, wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins, or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide remains the same. In various embodiments, the amino acid sequence of the one or more viral proteins, or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide remains the same before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
Various embodiments of the present invention provide for a polynucleotide encoding one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus, wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 20 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 20 amino acid substitutions, additions, or deletions is before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
Various embodiments of the present invention provide for a polynucleotide encoding one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus, wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 10 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 10 amino acid substitutions, additions, or deletions is before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
Various embodiments of the present invention provide for a polynucleotide encoding one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus, wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 12 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 12 amino acid substitutions, additions, or deletions is before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
In various embodiments, the amino acid sequence comprises up to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid sequence comprises 1-5, 6-10, 11-15, or 16-20 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid deletion, substitution, or addition results from nucleic acid deletion(s), substitution(s) or addition(s) before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
In various embodiments, the amino acid sequence comprises 12 amino acid deletions. In various embodiments, the amino acid sequence comprises 1-5, 6-10, 11-15, or 16-20 amino acid deletions. In various embodiments, the amino acid substitutions, additions, or deletions can be due to one or more point mutations in the recoded sequence. In various embodiments, the amino acid deletion, substitution, or addition results from nucleic acid deletion(s), substitution(s) or addition(s) before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
Thus, in various embodiments for these recoded polynucleotides (with or without the nucleic acid deletion(s), substitution(s) or addition(s)), the recoded polynucleotide can have a different length for the polyA tail; for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, or 54 consecutive adenines on the 3′ end; or for example, 1-6, 7-12, 13-18, 19-24, 25-30, 31-36, 37-42, 43-48, or 49-54 consecutive adenines on the 3′ end; or for example, 9-37, 12-34, 15-33, 18-30, or 21-27 consecutive adenines on the 3′ end; or for example, 19-25 consecutive adenines on the 3′ end.
In various embodiments, the polynucleotide is recoded by reducing codon-pair bias (CPB) or reducing codon usage bias compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, the polynucleotide is recoded by increasing the number of CpG or UpA di-nucleotides compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, each of the recoded one or more viral proteins, or each of the recoded one or more fragments thereof has a codon pair bias less than, −0.05, less than −0.1, less than −0.2, less than −0.3, or less than −0.4.
In certain embodiments, the recoded viral protein is RdRP and/or spike protein and each of the recoded viral protein or fragment thereof has a codon pair bias less than −0.05, or less than −0.06, or less than −0.07, or less than −0.08, or less than −0.09, or less than −0.1, or less than −0.11, or less than −0.12, or less than −0.13, or less than −0.14, or less than −0.15, or less than −0.16, or less than −0.17, or less than −0.18, or less than −0.19, or less than −0.2, or less than −0.25, or less than −0.3, or less than −0.35, or less than −0.4, or less than −0.45, or less than −0.5.
In certain embodiments, the recoded viral protein is RdRP and/or spike protein and each of the recoded viral protein or fragment thereof is reduced by at least 0.05, or at least 0.06, or at least 0.07, or at least 0.08, or at least 0.09, or at least 0.1, or at least 0.11, or at least 0.12, or at least 0.13, or at least 0.14, or at least 0.15, or at least 0.16, or at least 0.17, or at least 0.18, or at least 0.19, or at least 0.2, or at least 0.25, or at least 0.3, or at least 0.35, or at least 0.4, or at least 0.45, or at least 0.5, compared to the corresponding sequence on the parent sequence. In certain embodiments, it is in comparison corresponding sequence on the parent sequence from which the calculation is to be made; for example, the corresponding sequence of a wild-type virus.
In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type SARS-CoV-2 coronavirus. In various embodiments, the parent SARS-CoV-2 coronavirus is a natural isolate SARS-CoV-2 coronavirus.
In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type BetaCoV/Wuhan/IVDC-HB-01/2019 isolate of SARS-CoV-2 coronavirus. In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type Washington isolate of SARS-CoV-2 coronavirus (GenBank: MN985325.1), herein by reference as though fully set forth in its entirety.
In various embodiments, the parent SARS-CoV-2 coronavirus is a mutant form of the wild-type SARS-CoV-2 coronavirus sequence.
In various embodiments, the parent SARS-CoV-2 coronavirus is a SARS-CoV-2 variant. In various embodiments, SARS-CoV-2 variant is U.K. variant, South Africa variant, or Brazil variant.
Examples of the U.K. variant include but are not limited to GenBank Accession Nos. MW462650 (SARS-CoV-2/human/USA/MN-MDH-2252/2020), MW463056 (SARS-CoV-2/human/USA/FL-BPHL-2270/2020), and MW440433 (SARS-CoV-2/human/USA/NY-Wadsworth-291673-01/2020), all as of Jan. 19, 2021, all incorporated herein by reference as though fully set forth in their entirety. Additional examples of the U.K. variant include but are not limited to GISAID ID Nos. EPI_ISL_778842 (hCoV-19/USA/TX-CDC-9KXP-8438/2020; 2020-12-28), EPI_ISL_802609 (hCoV-19/USA/CA-CDC-STM-050/2020; 2020-12-28), EPI_ISL_802647 (hCoV-19/USA/FL-CDC-STM-043/2020; 2020-12-26), EPI_ISL_832014 (hCoV-19/USA/UT-UPHL-2101178518/2020; 2020-12-31), EPI_ISL_850618 (hCoV-19/USA/IN-CDC-STM-183/2020; 2020-12-31), and EPI_ISL_850960 (hCoV-19/USA/FL-CDC-STM-A100002/2021; 2021-01-04), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
Examples of the South Africa variant include but are not limited to GISAID ID Nos. EPI_ISL_766709 (hCoV-19/Sweden/20-13194/2020; 2020-12-24), EPI_ISL_768828 (hCoV-19/France/PAC-NRC2933/2020; 2020-12-22), EPI_ISL_770441 (hCoV-19/England/205280030/2020; 2020-12-24), and EPI_ISL_819798 (hCoV-19/England/OXON-F440A7/2020; 2020-12-18), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
Examples of the Brazil variant include but are not limited to GISAID ID Nos. EPI_ISL_677212 (hCoV-19/USA/VA-DCLS-2187/2020; 2020-11-12), EPI_ISL_723494 (hCoV-19/USA/VA-DCLS-2191/2020; 2020-11-12), EPI_ISL_845768 (hCoV-19/USA/GA-EHC-458R/2021; 2021-01-05), EPI_ISL_848196 (hCoV-19/Canada/LTRI-1192/2020; 2020-12-24), and EPI_ISL_848197 (hCoV-19/Canada/LTRI-1258/2020; 2020-12-24), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
In various embodiments, the parent SARS-CoV-2 coronavirus is a previously modified viral nucleic acid, or a previously attenuated viral nucleic acid.
In various embodiments, the polynucleotide is CPB deoptimized compared to its parent SARS-CoV-2 coronavirus polynucleotide. In various embodiments, the polynucleotide is codon deoptimized compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in humans. In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in a coronavirus. In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in a SARS-CoV-2 coronavirus. In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in a wild-type SARS-CoV-2 coronavirus.
In various embodiments, the polynucleotide comprises a recoded nucleotide sequence selected from RNA-dependent RNA polymerase (RdRP), a fragment of RdRP, a spike protein, a fragment of spike protein, and combinations thereof. In various embodiments, polynucleotide comprises a deletion of nucleotides that results in a deletion of amino acids in the spike protein that eliminates the furin cleavage site. While not wishing to be bound by any particular theory, the inventors believe that eliminating the furin cleavage site will be one of the drivers of safety of the vaccine and/or immune composition.
In various embodiments, the polynucleotide comprises at least one CPB deoptimized region selected from bp 11294-12709, bp 14641-15903, bp 21656-22306, bp 22505-23905, and bp 24110-25381 of SEQ ID NO:1 or SEQ ID NO:2.
In various embodiments, the polynucleotide comprises SEQ ID NO:3 (Wuhan-CoV_101K). In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 (e.g., without the polyA tail). In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, or 54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 1-6, 7-12, 13-18, 19-24, 25-30, 31-36, 37-42, 43-48, or 49-54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 9-37, 12-34, 15-33, 18-30, or 21-27 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 19-25 consecutive adenines on the 3′ end.
In various embodiment, the polynucleotide comprises SEQ ID NO:4. SEQ ID NO:4 is the deoptimized sequence in comparison to the wild-type WA-1 sequence (GenBank: MN985325.1 herein incorporated by reference as though fully set forth) (e.g., CDX-005). In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 (e.g., without the polyA tail). In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, or 54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises 1-29,834 of SEQ ID NO:4 and 1-6, 7-12, 13-18, 19-24, 25-30, 31-36, 37-42, 43-48, or 49-54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 and 9-37, 12-34, 15-33, 18-30, or 21-27 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 and 19-25 consecutive adenines on the 3′ end.
In various embodiments, the polynucleotide encodes SEQ ID NO:6 (recoded spike protein).
Various embodiments provide for a bacterial artificial chromosome (BAC) comprising a polynucleotide of the present invention. The polynucleotides of the present invention are the recoded polypeptides as discussed herein.
Various embodiments provide for a vector comprising a polynucleotide of the present invention. The polynucleotides of the present invention are the recoded polypeptides as discussed herein.
A cell comprising a vector of the present invention. The vectors are those as discussed herein.
In various embodiments, the cell is a Vero cell, HeLa Cell, baby hamster kidney (BHK) cell, MA104 cell, 293T Cell, BSR-T7 Cell, MRC-5 cell, CHO cell, or PER.C6 cell. In particular embodiments, the cell is Vero cell or baby hamster kidney (BHK) cell.
Various embodiments provide for a polypeptide encoded by a polynucleotide of the present invention. The polynucleotides of the present invention are the recoded polypeptides as discussed herein. The polypeptide exhibits properties that are different than a polypeptide encoded by the wild-type SARS-CoV-2 virus, or a polypeptide encoded by a SARS-CoV-2 variant. For example, the polypeptide encoded by recoded polynucleotides and deoptimized polynucleotides as discussed herein can exert attenuating properties to the virus.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus comprising a polypeptide encoded by a polynucleotide of the present invention. The polynucleotides of the present invention are the recoded polypeptides as discussed herein.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus comprising a polynucleotide of the present invention. The polynucleotides of the present invention are any one of the recoded polypeptides discussed herein.
In various embodiments, the expression of one or more of its viral proteins is reduced compared to its parent SARS-CoV-2 coronavirus.
In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type SARS-CoV-2 coronavirus. In various embodiments, the parent SARS-CoV-2 coronavirus is a natural isolate SARS-CoV-2 coronavirus.
In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type BetaCoV/Wuhan/IVDC-HB-01/2019 isolate of SARS-CoV-2 coronavirus. In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type Washington isolate of SARS-CoV-2 coronavirus (GenBank: MN985325.1), herein by reference as though fully set forth in its entirety.
In various embodiments, the parent SARS-CoV-2 coronavirus is a mutant form of the wild-type SARS-CoV-2 coronavirus sequence.
In various embodiments, the parent SARS-CoV-2 coronavirus is a SARS-CoV-2 variant. In various embodiments, SARS-CoV-2 variant is U.K. variant, South Africa variant, or Brazil variant.
Examples of the U.K. variant include but are not limited to GenBank Accession Nos. MW462650 (SARS-CoV-2/human/USA/MN-MDH-2252/2020), MW463056 (SARS-CoV-2/human/USA/FL-BPHL-2270/2020), and MW440433 (SARS-CoV-2/human/USA/NY-Wadsworth-291673-01/2020), all as of Jan. 19, 2021, all incorporated herein by reference as though fully set forth in their entirety. Additional examples of the U.K. variant include but are not limited to GISAID ID Nos. EPI_ISL_778842 (hCoV-19/USA/TX-CDC-9KXP-8438/2020; 2020-12-28), EPI_ISL_802609 (hCoV-19/USA/CA-CDC-STM-050/2020; 2020-12-28), EPI_ISL_802647 (hCoV-19/USA/FL-CDC-STM-043/2020; 2020-12-26), EPI_ISL_832014 (hCoV-19/USA/UT-UPHL-2101178518/2020; 2020-12-31), EPI_ISL_850618 (hCoV-19/USA/IN-CDC-STM-183/2020; 2020-12-31), and EPI_ISL_850960 (hCoV-19/USA/FL-CDC-STM-A100002/2021; 2021-01-04), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
Examples of the South Africa variant include but are not limited to GISAID ID Nos. EPI_ISL_766709 (hCoV-19/Sweden/20-13194/2020; 2020-12-24), EPI_ISL_768828 (hCoV-19/France/PAC-NRC2933/2020; 2020-12-22), EPI_ISL_770441 (hCoV-19/England/205280030/2020; 2020-12-24), and EPI_ISL_819798 (hCoV-19/England/OXON-F440A7/2020; 2020-12-18), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
Examples of the Brazil variant include but are not limited to GISAID ID Nos. EPI_ISL_677212 (hCoV-19/USA/VA-DCLS-2187/2020; 2020-11-12), EPI_ISL_723494 (hCoV-19/USA/VA-DCLS-2191/2020; 2020-11-12), EPI_ISL_845768 (hCoV-19/USA/GA-EHC-458R/2021; 2021-01-05), EPI_ISL_848196 (hCoV-19/Canada/LTRI-1192/2020; 2020-12-24), and EPI_ISL_848197 (hCoV-19/Canada/LTRI-1258/2020; 2020-12-24), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
In various embodiments, the parent SARS-CoV-2 coronavirus is a previously modified viral nucleic acid, or a previously attenuated viral nucleic acid.
In various embodiments the reduction in the expression of one or more of its viral proteins is reduced as the result of recoding a region selected RdRP protein, spike protein, and combinations thereof.
In various embodiments, the polynucleotide encodes one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus, wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins, or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide remains the same.
In various embodiments, the polynucleotide encodes one or more viral proteins or one or more fragments thereof of a parent SARS-CoV-2 coronavirus, wherein the polynucleotide is recoded compared to its parent SARS-CoV-2 coronavirus polynucleotide, and wherein the amino acid sequence of the one or more viral proteins or one or more fragments thereof of the parent SARS-CoV-2 coronavirus encoded by the polynucleotide comprises up to 15 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid sequence comprises up to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid substitutions, additions, or deletions. In various embodiments, the amino acid sequence comprises 12 amino acid deletions. In various embodiments, the amino acid sequence comprises 1-3, 4-6, 7-9, 10-12, or 13-15 amino acid deletions. The amino acid substitutions, additions, or deletions can be due to one or more point mutations in the recoded sequence. In various embodiments, the amino acid deletion, substitution, or addition results from nucleic acid deletion(s), substitution(s) or addition(s) before the polyA tail of the nucleic acid sequence of the parent SARS-CoV-2 virus sequence.
In various embodiments, the polynucleotide is recoded by reducing codon-pair bias (CPB) or reducing codon usage bias compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, the polynucleotide is recoded by increasing the number of CpG or UpA di-nucleotides compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, each of the recoded one or more viral proteins, or each of the recoded one or more fragments thereof has a codon pair bias less than, −0.05, less than −0.1, less than −0.2, less than −0.3, or less than −0.4.
In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type SARS-CoV-2 coronavirus. In various embodiments, the parent SARS-CoV-2 coronavirus is a natural isolate SARS-CoV-2 coronavirus.
In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type BetaCoV/Wuhan/IVDC-HB-01/2019 isolate of SARS-CoV-2 coronavirus. In various embodiments, the parent SARS-CoV-2 coronavirus is wild-type Washington isolate of SARS-CoV-2 coronavirus (GenBank: MN985325.1), herein by reference as though fully set forth in its entirety.
In various embodiments, the parent SARS-CoV-2 coronavirus is a mutant form of the wild-type SARS-CoV-2 coronavirus sequence.
In various embodiments, the parent SARS-CoV-2 coronavirus is a SARS-CoV-2 variant. In various embodiments, SARS-CoV-2 variant is U.K. variant, South Africa variant, or Brazil variant.
Examples of the U.K. variant include but are not limited to GenBank Accession Nos. MW462650 (SARS-CoV-2/human/USA/MN-MDH-2252/2020), MW463056 (SARS-CoV-2/human/USA/FL-BPHL-2270/2020), and MW440433 (SARS-CoV-2/human/USA/NY-Wadsworth-291673-01/2020), all as of Jan. 19, 2021, all incorporated herein by reference as though fully set forth in their entirety. Additional examples of the U.K. variant include but are not limited to GISAID ID Nos. EPI_ISL_778842 (hCoV-19/USA/TX-CDC-9KXP-8438/2020; 2020-12-28), EPI_ISL_802609 (hCoV-19/USA/CA-CDC-STM-050/2020; 2020-12-28), EPI_ISL_802647 (hCoV-19/USA/FL-CDC-STM-043/2020; 2020-12-26), EPI_ISL_832014 (hCoV-19/USA/UT-UPHL-2101178518/2020; 2020-12-31), EPI_ISL_850618 (hCoV-19/USA/IN-CDC-STM-183/2020; 2020-12-31), and EPI_ISL_850960 (hCoV-19/USA/FL-CDC-STM-A100002/2021; 2021-01-04), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
Examples of the South Africa variant include but are not limited to GISAID ID Nos. EPI_ISL_766709 (hCoV-19/Sweden/20-13194/2020; 2020-12-24), EPI_ISL_768828 (hCoV-19/France/PAC-NRC2933/2020; 2020-12-22), EPI_ISL_770441 (hCoV-19/England/205280030/2020; 2020-12-24), and EPI_ISL_819798 (hCoV-19/England/OXON-F440A7/2020; 2020-12-18), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
Examples of the Brazil variant include but are not limited to GISAID ID Nos. EPI_ISL_677212 (hCoV-19/USA/VA-DCLS-2187/2020; 2020-11-12), EPI_ISL_723494 (hCoV-19/USA/VA-DCLS-2191/2020; 2020-11-12), EPI_ISL_845768 (hCoV-19/USA/GA-EHC-458R/2021; 2021-01-05), EPI_ISL_848196 (hCoV-19/Canada/LTRI-1192/2020; 2020-12-24), and EPI_ISL_848197 (hCoV-19/Canada/LTRI-1258/2020; 2020-12-24), all as of Jan. 20, 2021, and all incorporated herein by reference as though fully set forth in their entirety.
In various embodiments, the parent SARS-CoV-2 coronavirus is a previously modified viral nucleic acid, or a previously attenuated viral nucleic acid.
In various embodiments, the polynucleotide is CPB deoptimized compared to its parent SARS-CoV-2 coronavirus polynucleotide. In various embodiments, the polynucleotide is codon deoptimized compared to its parent SARS-CoV-2 coronavirus polynucleotide.
In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in humans. In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in a coronavirus. In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in a SARS-CoV-2 coronavirus. In various embodiments, the codon-deoptimized or CPB deoptimized is based on frequently used codons or CPB in a wild-type SARS-CoV-2 coronavirus.
In various embodiments, the polynucleotide comprises a recoded nucleotide sequence selected from RNA-dependent RNA polymerase (RdRP), a fragment of RdRP, a spike protein, a fragment of spike protein, and combinations thereof. In various embodiments, polynucleotide comprises a deletion of nucleotides that results in a deletion of amino acids in the spike protein that eliminates the furin cleavage site. While not wishing to be bound by any particular theory, the inventors believe that eliminating the furin cleavage site will be one of the drivers of safety of the vaccine and/or immune composition.
In various embodiments, the polynucleotide comprises at least one CPB deoptimized region selected from bp 11294-12709, bp 14641-15903, bp 21656-22306, bp 22505-23905, and bp 24110-25381 of SEQ ID NO:1 or SEQ ID NO:2.
In various embodiments, the polynucleotide comprises SEQ ID NO:3 (Wuhan-CoV_101K). In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 (e.g., without the polyA tail). In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, or 54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 1-6, 7-12, 13-18, 19-24, 25-30, 31-36, 37-42, 43-48, or 49-54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 9-37, 12-34, 15-33, 18-30, or 21-27 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,877 of SEQ ID NO:3 and 19-25 consecutive adenines on the 3′ end.
In various embodiment, the polynucleotide comprises SEQ ID NO:4. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 (e.g., without the polyA tail). In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, or 54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises 1-29,834 of SEQ ID NO:4 and 1-6, 7-12, 13-18, 19-24, 25-30, 31-36, 37-42, 43-48, or 49-54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 and 9-37, 12-34, 15-33, 18-30, or 21-27 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:4 and 19-25 consecutive adenines on the 3′ end.
In various embodiment, the polynucleotide comprises SEQ ID NO:7. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:7 (e.g., without the polyA tail). In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:7 and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, or 54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises 1-29,834 of SEQ ID NO:7 and 1-6, 7-12, 13-18, 19-24, 25-30, 31-36, 37-42, 43-48, or 49-54 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:7 and 9-37, 12-34, 15-33, 18-30, or 21-27 consecutive adenines on the 3′ end. In various embodiments, the polynucleotide comprises nucleotides 1-29,834 of SEQ ID NO:7 and 19-25 consecutive adenines on the 3′ end.
In various embodiments, the polynucleotide encodes SEQ ID NO:6 (recoded spike protein).
Various embodiments provide for an immune composition for inducing an immune response in a subject, comprising: a modified SARS-CoV-2 coronavirus of the present invention. The modified SARS-CoV-2 coronavirus is any one of the modified SARS-CoV-2 coronavirus discussed herein. In various embodiments, the modified SARS-CoV-2 coronavirus of the present invention is a live-attenuated virus. In some embodiments the immune composition further comprises an acceptable excipient or carrier as described herein. In some embodiments, the immune composition further comprises a stabilizer as described herein. In some embodiments, the immune composition further comprise an adjuvant as described herein. In some embodiments, the immune composition further comprises sucrose, glycine or both. In various embodiments, the immune composition further comprises about sucrose (5%) and about glycine (5%). In various embodiments, the acceptable carrier or excipient is selected from the group consisting of a sugar, amino acid, surfactant and combinations thereof. In various embodiments, the amino acid is at a concentration of about 5% w/v. Nonlimiting examples of suitable amino acids include arginine and histidine. Nonlimiting examples of suitable carriers include gelatin and human serum albumin. Nonlimiting examples of suitable surfactants include nonionic surfactants such as Polysorbate 80 at very low concentration of 0.01-0.05%.
In various embodiments, the immune composition is provided at dosages of about 103-107 PFU. In various embodiments, the immune composition is provided at dosages of about 104-106 PFU. In various embodiments, the immune composition is provided at a dosage of about 103 PFU. In various embodiments, the immune composition is provided at a dosage of about 104 PFU. In various embodiments, the immune composition is provided at a dosage of about 105 PFU. In various embodiments, the immune composition is provided at a dosage of about 106 PFU. In various embodiments, the immune composition is provided at a dosage of about 107 PFU.
In various embodiments, the immune composition is provided at a dosage of about 5×103 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×104 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×105 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×106 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×107 PFU.
Various embodiments provide for a vaccine composition for inducing an immune response in a subject, comprising: a modified SARS-CoV-2 coronavirus of the present invention. The modified SARS-CoV-2 coronavirus is any one of the modified SARS-CoV-2 coronavirus discussed herein. In various embodiments, the modified SARS-CoV-2 coronavirus of the present invention is a live-attenuated virus. In some embodiments the vaccine composition further comprises an acceptable carrier or excipient as described herein. In some embodiments, the immune composition further comprises a stabilizer as described herein. In some embodiments, the vaccine composition further comprise an adjuvant as described herein. In some embodiments, the vaccine composition further comprises sucrose, glycine or both. In various embodiments, the vaccine composition further comprises sucrose (5%) and glycine (5%). In various embodiments, the acceptable carrier or excipient is selected from the group consisting of a sugar, amino acid, surfactant and combinations thereof. In various embodiments, the amino acid is at a concentration of about 5% w/v. Nonlimiting examples of suitable amino acids include arginine and histidine. Nonlimiting examples of suitable carriers include gelatin and human serum albumin. Nonlimiting examples of suitable surfactants include nonionic surfactants such as Polysorbate 80 at very low concentration of 0.01-0.05%.
In various embodiments, the vaccine composition is provided at dosages of about 103-107 PFU. In various embodiments, the vaccine composition is provided at dosages of about 104-106 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 103 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 104 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 105 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 106 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 107 PFU.
In various embodiments, the immune composition is provided at a dosage of about 5×103 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×104 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×105 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×106 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×107 PFU.
Various embodiments provide for a vaccine composition for inducing a protective immune response in a subject, comprising: a modified SARS-CoV-2 coronavirus of the present invention. The modified SARS-CoV-2 coronavirus is any one of the modified SARS-CoV-2 coronavirus discussed herein. In various embodiments, the modified SARS-CoV-2 coronavirus of the present invention is a live-attenuated virus. In some embodiments the vaccine composition further comprises an acceptable carrier or excipient as described herein. In some embodiments, the vaccine composition further comprise an adjuvant as described herein. In some embodiments, the vaccine composition further comprises sucrose, glycine or both. In various embodiments, the vaccine composition further comprises sucrose (5%) and glycine (5%). In various embodiments, the acceptable carrier or excipient is selected from the group consisting of a sugar, amino acid, surfactant and combinations thereof. In various embodiments, the amino acid is at a concentration of about 5% w/v. Nonlimiting examples of suitable amino acids include arginine and histidine. Nonlimiting examples of suitable carriers include gelatin and human serum albumin. Nonlimiting examples of suitable surfactants include nonionic surfactants such as Polysorbate 80 at very low concentration of 0.01-0.05%.
In various embodiments, the vaccine composition is provided at dosages of about 103-107 PFU. In various embodiments, the vaccine composition is provided at dosages of about 104-106 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 103 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 104 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 105 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 106 PFU. In various embodiments, the vaccine composition is provided at a dosage of about 107 PFU.
In various embodiments, the immune composition is provided at a dosage of about 5×103 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×104 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×105 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×106 PFU. In various embodiments, the immune composition is provided at a dosage of about 5×107 PFU.
It should be understood that an attenuated virus of the invention, where used to elicit an immune response in a subject (or protective immune response) or to prevent a subject from or reduce the likelihood of becoming afflicted with a virus-associated disease, can be administered to the subject in the form of a composition additionally comprising a pharmaceutically acceptable carrier or excipient. Pharmaceutically acceptable carriers and excipients are known to those skilled in the art and include, but are not limited to, one or more of 0.01-0.1M and preferably 0.05M phosphate buffer, phosphate-buffered saline (PBS), DMEM, L-15, a 10-25% sucrose solution in PBS, a 10-25% sucrose solution in DMEM, or 0.9% saline. Such carriers also include aqueous or non-aqueous solutions, suspensions, and emulsions. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, saline and buffered media. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's and fixed oils. Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers such as those based on Ringer's dextrose, and the like. Solid compositions may comprise nontoxic solid carriers such as, for example, glucose, sucrose, mannitol, sorbitol, lactose, starch, magnesium stearate, cellulose or cellulose derivatives, sodium carbonate, gelatin, recombinant human serum albumin, human serum albumin, and/or magnesium carbonate. For administration in an aerosol, such as for pulmonary and/or intranasal delivery, an agent or composition is preferably formulated with a nontoxic surfactant, for example, esters or partial esters of C6 to C22 fatty acids or natural glycerides, and a propellant. Additional carriers such as lecithin may be included to facilitate intranasal delivery. Pharmaceutically acceptable carriers or excipients can further comprise minor amounts of auxiliary substances such as wetting or emulsifying agents, preservatives and other additives, such as, for example, antimicrobials, antioxidants and chelating agents, which enhance the shelf life and/or effectiveness of the active ingredients. The instant compositions can, as is well known in the art, be formulated so as to provide quick, sustained or delayed release of the active ingredient after administration to a subject.
In various embodiments, the vaccine composition or immune composition is formulated for delivery intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the vaccine composition or immune composition is formulated for delivery intranasally. In various embodiments, the vaccine composition or immune composition is formulated for delivery via a nasal drop or nasal spray.
Various embodiments provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a dose of an immune composition the present invention. The immune composition is any one of the immune composition discussed herein. In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, the immune composition is administered intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the immune composition is administered intranasally. In various embodiments, the immune composition is administered via a nasal drop or nasal spray.
Various embodiments provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a dose of a vaccine composition the present invention. The vaccine composition is any one of the vaccine composition discussed herein. In various embodiments, the immune response is a protective immune response. In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, the vaccine composition is administered intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the vaccine composition is administered intranasally. In various embodiments, the vaccine composition is administered via a nasal drop or nasal spray.
Various embodiments provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a dose of a modified SARS-CoV-2 coronavirus of the present invention. The modified SARS-CoV-2 coronavirus is any one of the modified SARS-CoV-2 coronavirus discussed herein. In various embodiments, the immune response is a protective immune response. In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, the dose is about 103-107 PFU. In various embodiments, the dose is about 104-106 PFU. In various embodiments, the dose is about 103 PFU. In various embodiments, the dose is about 104 PFU. In various embodiments, the dose is about 105 PFU. In various embodiments, the dose is about 106 PFU. In various embodiments, the dose is about 107 PFU.
In various embodiments, the dose is about 5×103 PFU. In various embodiments, the dose is about 5×104 PFU. In various embodiments, the dose is about 5×105 PFU. In various embodiments, the dose is about 5×106 PFU. In various embodiments, the dose is about 5×107 PFU.
In various embodiments, the modified SARS-CoV-2 coronavirus is administered intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the modified SARS-CoV-2 coronavirus is administered intranasally. In various embodiments, the modified SARS-CoV-2 coronavirus is administered via a nasal drop or nasal spray.
Various embodiments provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a prime dose of a modified SARS-CoV-2 coronavirus of the present invention; and administering to the subject one or more boost doses of a modified SARS-CoV-2 coronavirus of the present invention. The modified SARS-CoV-2 coronavirus is any one of the modified SARS-CoV-2 coronavirus discussed herein. In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, the prime dose and/or the one or more boost doses of the modified SARS-CoV-2 coronavirus is administered intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the prime dose and/or the one or more boost doses of the modified SARS-CoV-2 coronavirus is administered intranasally. In various embodiments, the prime dose and/or the one or more boost doses of the modified SARS-CoV-2 coronavirus is administered via a nasal drop or nasal spray.
Various embodiments provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a prime dose of an immune composition of the present invention; and administering to the subject one or more boost doses of an immune composition of the present invention. The immune composition is any one of the immune composition discussed herein. In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, the prime dose and/or the one or more boost doses of the immune composition is administered intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the prime dose and/or the one or more boost doses of the immune composition is administered intranasally. In various embodiments, the prime dose and/or the one or more boost doses of the immune composition is administered via a nasal drop or nasal spray.
Various embodiments provide for a method of eliciting an immune response in a subject, comprising: administering to the subject a prime dose of a vaccine composition of the present invention; and administering to the subject one or more boost doses of a vaccine composition of the present invention. The vaccine composition is any one of the vaccine composition discussed herein. In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, the prime dose and/or the one or more boost doses of the vaccine composition is administered intravenously, or intrathecally, subcutaneously, intramuscularly, intradermally or intranasally. In various embodiments, the prime dose and/or the one or more boost doses of the vaccine composition is administered intranasally. In various embodiments, the prime dose and/or the one or more boost doses of the vaccine composition is administered via a nasal drop or nasal spray.
The timing between the prime and boost dosages can vary, for example, depending on the stage of infection or disease (e.g., non-infected, infected, number of days post infection), and the patient's health. In various embodiments, the one or more boost dose is administered about 2 weeks after the prime dose. That is, the prime dose is administered and about two weeks thereafter, a boost dose is administered. In various embodiments, the one or more boost dose is administered about 4 weeks after the prime dose. In various embodiments, the one or more boost dose is administered about 6 weeks after the prime dose. In various embodiments, the one or more boost dose is administered about 8 weeks after the prime dose. In various embodiments, the one or more boost dose is administered about 12 weeks after the prime dose. In various embodiments, the one or more boost dose is administered about 1-12 weeks after the prime dose.
In various embodiments, the one or more boost doses can be given as one boost dose. In other embodiments, the one or more boost doses can be given as a boost dose periodically. For example, it can be given quarterly, every 4 months, every 6 months, yearly, every 2 years, every 3 years, every 4 years, every 5 years, every 6 years, every 7 years, every 8 years, every 9 years, or every 10 years.
In various embodiments, the prime dose and boost does are each about 103-107 PFU. In various embodiments, the prime dose and boost does are each about 104-106 PFU. In various embodiments, the prime dose and boost does are each about 103 PFU. In various embodiments, the prime dose and boost does are each about 104 PFU. In various embodiments, the prime dose and boost does are each about 105 PFU. In various embodiments, the prime dose and boost does are each about 106 PFU. In various embodiments, the dose is about 107 PFU.
In various embodiments, the prime dose and boost does are each about 5×103 PFU. In various embodiments, the prime dose and boost does are each about 5×104 PFU. In various embodiments, the prime dose and boost does are each about 5×105 PFU. In various embodiments, the prime dose and boost does are each about 5×106 PFU. In various embodiments, the prime dose and boost does are each about 5×107 PFU.
In various embodiments, the dosage for the prime dose and the boost dose is the same.
In various embodiments, the dosage amount can vary between the prime and boost dosages. As a non-limiting example, the prime dose can contain fewer copies of the virus compared to the boost dose. For example, the prime dose is about 103 PFU and the boost dose is about 104-106 PFU, or, the prime dose is about 104 and the boost dose is about 105-107 PFU.
In various embodiments, wherein the boost dose is administered periodically, the subsequent boost doses can be less than the first boost dose.
As another non-limiting example, the prime dose can contain more copies of the virus compared to the boost dose.
In various embodiments, the immune response is a protective immune response.
In various embodiments, the dose is a prophylactically effective or therapeutically effective dose.
In various embodiments, intranasal administration of a modified SARS-CoV-2 coronavirus of the present invention, the immune composition of the present invention or the vaccine composition of the present invention comprises: instructing the subject blow the nose and tilt the head back; optionally, instructing the subject reposition the head to avoid having composition dripping outside of the nose or down the throat; administering about 0.25 mL comprising the dosage into each nostril; instructing the subject to sniff gently; and instructing the subject to not blow the nose for a period of time; for example, about 60 minutes.
In some embodiments, the subject is not taking any immunosuppressive medications. In various embodiments, the subject is not taking any immunosuppressive medications about 180 days, 150 days, 120 days, 90 days, 75 days, 60 days, 45 days, 30 days, 15 days or 7 days before the administration of the modified SARS-CoV-2 coronavirus of the present invention, the immune composition of the present invention or the vaccine composition of the present invention. In various embodiments, the subject does not take any immunosuppressive medications for about 1 day, 7 days, 14 days, 30 days, 45 days, 60 days, 75 days, 90 days, 120 days, 150 days, 180 days, 9 months, 12 months, 15 months, 18 months, 21 months, or 24 months after the administration of the modified SARS-CoV-2 coronavirus of the present invention, the immune composition of the present invention or the vaccine composition of the present invention.
Immunosuppressive medications (including, but not limited to, the following: Corticosteroids (e.g., prednisone (Deltasone, Orasone), budesonide (Entocort EC), prednisolone (Millipred)), Calcineurin inhibitors (e.g., cyclosporine (Neoral, Sandimmune, SangCya), tacrolimus (Astagraf XL, Envarsus XR, Prograf), Mechanistic target of rapamycin (mTOR) inhibitors (e.g., sirolimus (Rapamune), everolimus (Afinitor, Zortress)), Inosine monophosphate dehydrogenase (IMDH) inhibitors, (e.g., azathioprine (Azasan, Imuran), leflunomide (Arava), mycophenolate (CellCept, Myfortic)), Biologics (e.g., abatacept (Orencia), adalimumab (Humira), anakinra (Kineret), certolizumab (Cimzia), etanercept (Enbrel), golimumab (Simponi), infliximab (Remicade), ixekizumab (Taltz), natalizumab (Tysabri), rituximab (Rituxan), secukinumab (Cosentyx), tocilizumab (Actemra), ustekinumab (Stelara), vedolizumab (Entyvio)), Monoclonal antibodies (e.g., basiliximab (Simulect), daclizumab (Zinbryta), muromonab (Orthoclone OKT3)).
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention for use in eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19.
Various embodiments of the present invention provide for a modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention for use in eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19, wherein the use comprises a prime dose of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention, and one or more boost doses of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention.
Various embodiments of the present invention provide for a use of modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention in the manufacture of a medicament for eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19.
Various embodiments of the present invention provide for a use of modified SARS-CoV-2 coronavirus of the present invention, a vaccine composition of the present invention, or an immune composition of the present invention in the manufacture of a medicament for use in eliciting an immune response, or for therapeutic or prophylactic treatment of COVID-19, wherein the medicament comprises a prime dose of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention, and one or more boost doses of the modified SARS-CoV-2 coronavirus of the present invention, or the vaccine composition of the present invention, or the immune composition of the present invention.
The modified SARS-CoV-2 coronavirus of the present invention is any one of the modified SARS-CoV-2 coronavirus discussed herein. The vaccine composition of the present invention is any one of the vaccine compositions discussed herein. The immune composition of the present invention is any one of the immune compositions discussed herein.
In various embodiments, the immune response is a protective immune response.
Various embodiments provide for a method of making a modified SARS-CoV-2 coronavirus, comprising: obtaining a nucleotide sequence encoding one or more proteins of a parent SARS-CoV-2 coronavirus or one or more fragments thereof, recoding the nucleotide sequence to reduce protein expression of the one or more proteins, or the one or more fragments thereof, and substituting a nucleic acid having the recoded nucleotide sequence into the parent SARS-CoV-2 coronavirus genome to make the modified SARS-CoV-2 coronavirus genome, wherein expression of the recoded nucleotide sequence is reduced compared to the parent virus.
In various embodiments, the parent SARS-CoV-2 coronavirus is a wild-type (wt) viral nucleic acid. In various embodiments, the parent SARS-CoV-2 coronavirus is a natural isolate viral nucleic acid. In various embodiments, the parent SARS-CoV-2 coronavirus is a previously modified viral nucleic acid, or a previously attenuated viral nucleic acid. In various embodiments, the parent SARS-CoV-2 coronavirus is a SARS-CoV-2 variant.
In various embodiment, making the modified SARS-CoV-2 coronavirus genome comprises using a cloning host.
In various embodiment, making the modified SARS-CoV-2 coronavirus genome comprises constructing an infectious cDNA clone, using BAC vector, using an overlap extension PCR strategy, or long PCR-based fusion strategy.
In various embodiment, the modified SARS-CoV-2 coronavirus genome further comprises one or more mutations, including deletion, substitutions and additions. One or more can be 1-5, 6-10, 11-15, 16-20, 21-25, 26-30, 31-35, 36-40, 41-45, 46-50, 51-60, 61-70, 71-80, 81-90, or 91-100 mutations.
In various embodiments, recoding the nucleotide sequence to reduce protein expression of the one or more proteins, or the one or more fragments thereof is by way of reducing codon-pair bias (CPB) compared to its parent SARS-CoV-2 coronavirus polynucleotide, reducing codon usage bias compared to its parent SARS-CoV-2 coronavirus polynucleotide, or increasing the number of CpG or UpA di-nucleotides compared to its parent SARS-CoV-2 coronavirus polynucleotide, as discuss herein.
Various embodiments of the present invention provide for a method of generating an attenuated, comprising: transfection a population of cells with a vector comprising the viral genome; passaging the population of cells in a cell culture at least one time; collecting supernatant from cell culture.
In various embodiments, the method further comprises concentrating the supernatant.
In various embodiments, the method comprises passaging the population of cells 2 to 15 times; and collecting supernatant from the cell culture of the population of cells. In various embodiments, the method comprises passaging the population of cells 2 to 10 times; and collecting supernatant from the cell culture of the population of cells. In various embodiments, the method comprises passaging the population of cells 2 to 7 times; and collecting supernatant from the cell culture of the population of cells. In various embodiments, the method comprises passaging the population of cells 2 to 5 times; and collecting supernatant from the cell culture of the population of cells. In various embodiments, the method comprises passaging the population of cells 2, 3, 4, 5, 6, 7, 8, or 10 times; and collecting supernatant from the cell culture of the population of cells. In various embodiments, collecting supernatant from the cell culture is done during each passage of the population of cells. In other embodiments, collecting supernatant from the cell culture is done during one or more passages of the population of cells. For example, it can be done every other passage; every two passage, every three passage, etc.
The present invention is also directed to a kit to vaccinate a subject, to elicit an immune response or to elicit a protective immune response in a subject. The kit is useful for practicing the inventive method of elicit an immune response or to elicit a protective immune response. The kit is an assemblage of materials or components, including at least one of the inventive compositions. Thus, in some embodiments the kit contains a composition including any one of the modified SARS-CoV-2 virus discussed herein, any one of the immune compositions discussed herein, or any one of the vaccine compositions discussed herein of the present invention. Thus, in some embodiments the kit contains unitized single dosages of the composition including the modified SARS-CoV-2 virus, the immune compositions, or the vaccine compositions of the present invention as described herein; for example, each vial contains enough for a dose of about 103-107 PFU of the modified SARS-CoV-2 virus, or more particularly, 104-106 PFU of the modified SARS-CoV-2 virus, 104 PFU of the modified SARS-CoV-2 virus, 105 PFU of the modified SARS-CoV-2 virus, or 106 PFU of the modified SARS-CoV-2 virus; or more particularly, 5×104-5×106 PFU of the modified SARS-CoV-2 virus, 5×104 PFU of the modified SARS-CoV-2 virus, 5×105 PFU of the modified SARS-CoV-2 virus, or 5×106 PFU of the modified SARS-CoV-2 virus. In various embodiments, the kit contains multiple dosages of the composition including the modified SARS-CoV-2 virus, the immune compositions, or the vaccine compositions of the present invention as described herein; for example, if the kit contains 10 dosages per vial, each vial contains about 10×103-107 PFU of the modified SARS-CoV-2 virus, or more particularly, 10×104-106 PFU of the modified SARS-CoV-2 virus, 10×104 PFU of the modified SARS-CoV-2 virus, 10×105 PFU of the modified SARS-CoV-2 virus, or 10×106 PFU of the modified SARS-CoV-2 virus, or more particularly, 50×104-50×106 PFU of the modified SARS-CoV-2 virus, 50×104 PFU of the modified SARS-CoV-2 virus, 50×105 PFU of the modified SARS-CoV-2 virus, or 50×106 PFU of the modified SARS-CoV-2 virus.
The exact nature of the components configured in the inventive kit depends on its intended purpose. For example, some embodiments are configured for the purpose of vaccinating a subject, for eliciting an immune response or for eliciting a protective immune response in a subject. In one embodiment, the kit is configured particularly for the purpose of prophylactically treating mammalian subjects. In another embodiment, the kit is configured particularly for the purpose of prophylactically treating human subjects. In further embodiments, the kit is configured for veterinary applications, treating subjects such as, but not limited to, farm animals, domestic animals, and laboratory animals.
Instructions for use may be included in the kit. “Instructions for use” typically include a tangible expression describing the technique to be employed in using the components of the kit to effect a desired outcome, such as to vaccinate a subject, to elicit an immune response or to elicit a protective immune response in a subject. For example, for nasal administration, instructions for use can include but are not limited to instructions for the subject to blow the nose and tilt the head back, instructions for the subject reposition the head to avoid having composition dripping outside of the nose or down the throat, instructions for administering about 0.25 mL comprising the dosage into each nostril; instructions for the subject to sniff gently, and/or instructions for the subject to not blow the nose for a period of time; for example, about 60 minutes. Further instructions can include instruction for the subject to not take any immunosuppressive medications
Optionally, the kit also contains other useful components, such as, diluents, buffers, pharmaceutically acceptable carriers, syringes, droppers, catheters, applicators, pipetting or measuring tools, bandaging materials or other useful paraphernalia as will be readily recognized by those of skill in the art.
The materials or components assembled in the kit can be provided to the practitioner stored in any convenient and suitable ways that preserve their operability and utility. For example, the components can be in dissolved, dehydrated, or lyophilized form; they can be provided at room, refrigerated or frozen temperatures. The components are typically contained in suitable packaging material(s). As employed herein, the phrase “packaging material” refers to one or more physical structures used to house the contents of the kit, such as inventive compositions and the like. The packaging material is constructed by known methods, preferably to provide a sterile, contaminant-free environment. The packaging materials employed in the kit are those customarily utilized in vaccines. As used herein, the term “package” refers to a suitable solid matrix or material such as glass, plastic, paper, foil, and the like, capable of holding the individual kit components. Thus, for example, a package can be a glass vial used to contain suitable quantities of an inventive composition containing modified SARS-CoV-2 virus, the immune compositions, or the vaccine compositions of the present invention as described herein. The packaging material generally has an external label which indicates the contents and/or purpose of the kit and/or its components.
The following examples are provided to better illustrate the claimed invention and are not to be interpreted as limiting the scope of the invention. To the extent that specific materials are mentioned, it is merely for purposes of illustration and is not intended to limit the invention. One skilled in the art may develop equivalent means or reactants without the exercise of inventive capacity and without departing from the scope of the invention.
Step 1: PCR and Gel Purification. Primers and Templates. To Start from T7 Promoter
To include the pCMV in fragment 0
Step 2: Overlapping PCR
May need to overlap 4-5 pieces first—purify the products—then overlap to get the full length genome.
Step 3:
Option 1: Use directly for in vitro transcription/store as overlapping PCR product;
Option 2: Clone into pCC1BAC vector
To clone the CoV genome into pCC1BAC vector, use #1883 and 1890 as forward and reverse primers for amplifying fragment0 and fragment 19, as well as in final amplification after overlapping. Assemble with Bsa I carrying pCC1BAC using NEB Golden gate assembly.
Clone into pGGA Vector (from Golden Gate Clone Kit) Through Bsa I Sites, then Clone into pCC1BAC Vector Through Bsa I Site
pCC1BAC obtained from existing pCC1-CysS-CD plasmid and need modification—see “pCC1BAC Modification”
Step 1: PCR and Gel Purification
Primers and Templates—To start from T7 promoter
To include the pCMV in ordered fragment 0
Step 2: Assembly viral genome into 4 large fragments into pGGA using NEB Golden gate assembly kit
Fragment 0 (or 1)-4, 5-9, 10-14 and 15-19.
Follow NEB Golden gate assembly kit menu
Step 3 PCR viral fragments from pGGA clones for next step assembly (also introduce new Bsa I sites)
Step 3.1: Re-Introduce Bsa I Through PCR and Gel Purification (Individually)
Step 3.2 Assemble the 4 Large Fragments into pCC1BAC Using NEB Golden Gate Assembly Kit
Assemble all Fragments into pCC1BAC Vector Directly
Step 1: PCR and Gel Purification
Step 2: Assembly Full Viral Genome in pCC1BAC Vector Following NEB Golden Gate Assembly Kit Menu
Step 1: PCR and gel purification. Same as example 1. For fragment 0 and fragment 19, need to use alternative primer for PCR and for 5′ and 3′ end of pCC1BAC.
For intersection between pCC1BAC and viral genome
Step 2: Assembly Follow NEBuilder HiFi Menu
Modification of pCC1BAC vector. The backbone if the pCC1BAC is obtained from pCC1-CysS-CD plasmid. It carries internal Bsa I and Bsm BI sites. This modification is to remove these sites. It also removes the region between the 2 Not I sites, and nt8104-8139(?).
Step 1: PCR and Gel Purification
Step 2: Overlapping PCR. For this method—NEBuilder, use alternative primers.
Coronavirus strain 2019-nCoV/USA-WA1/2020 (“WA1”) (BEI Resources NR-52281, Lot 70034262) was distributed by BEI Resources after 3 passages on Vero (CCL81) at CDC, and one passage on Vero E6 at BEI Resources. The full virus genome sequence after 4 passages was determined by CDC and found to contain no nucleotide differences (Harcourt et al., 2020) compared to the clinical specimen from which it was derived (GenBank Accession MN985325) Upon receipt, WA1 and was amplified by a further two passages on Vero E6 cells in DMEM containing 2% FBS at 37° C.
Passage 6 WA1 virus was used to purify viral genome RNA by extraction with Trizol reagent (Thermo Fisher) according to standard protocols. Briefly, 0.5 ml virus sample with a titer of 1×10{circumflex over ( )}7 PFU/ml was extracted with an equal volume of Trizol. The procedure had previously been validated in four separate experiment to completely inactivate SARS-CoV2 virus infectivity. After phase separation by addition of 0.1 ml chloroform, the RNA in aqueous phase was precipitated with an equal volume of isopropanol. The precipitated RNA was washed in 70% ethanol, dried, and resuspended in 20 ul RNAse-free water.
Viral cDNA Generation
Wild-type cDNA were synthesized using SuperScript IV First Strand Synthesis system. In each reaction, a total reaction volume of 13 μl for Tube #1 was set up as follows:
The sample was mixed and incubated at 65° C. for 5 minutes, then immediately put on ice for 1 minute. Another tube (Tube #2) was prepared with a total reaction volume of 7 μl:
We mixed Tube #1 and Tube #2, for a total reaction volume of 20 μl, and incubated at 23° C. for 10 minutes, followed by 50° C. for 50 minutes, and 80° C. for 10 minutes to generate cDNA.
Q5 High-Fidelity 2× Master Mixture (NEB, Ipswich, Mass.) were used to amplify genome fragments from cDNA.
The 20 μl reaction containing 1 μl fresh-made cDNA, 1 μl of forward and reverse primers (detailed in Table 4) at 0.5 μM concentration, 10 μl of the 2×Q5 master mixture and H2O. Reaction parameters were as follows: 98° C. 30 sec to initiate the reaction, followed by 30 cycles of 98° C. for 10 sec, 60° C. for 30 seconds, and 65° C. for 1 min and a final extension at 65° C. for 5 min. Totally 19 genome fragments, all about 1.8 Kb except fragment 19 (about 1.2 Kb) were obtained, which cover the whole viral genome with 200 bp overlapping region between any two of them using specific primers (Table 4). Amplicons were verified by agarose gel electrophoresis (
Q5® High-Fidelity DNA Polymerase (NEB, Ipswich, Mass.) were used to re-construct the whole COVID-19 genome.
First, all 19 genome fragments were used in an overlapping reaction to reconstruct the full genome. Briefly, a mixture with 30-40 ng of each DNA fragment (the molar ratio among all pieces are at 1:1), 10 μl 5× reaction buffer, 1 μl 10 mM dNTP, 0.5 μl Q5 polymerase and H2O to a final volume of 50 μl was made. The reaction was carried out under following condition: 98° C. for 30 sec, and 72° C. for 16 min 30 sec for 10 cycles.
Next, 2 μl overlapping reaction product were mixed with 4 μl 5× reaction buffer, 1 μl 10 mM dNTP, 1 μl of each flanking primers at 0.5 μM, 0.241 Q5 polymerase and H2O to a final volume of 20 μl and PCR was carried out as follows: 98° C. 30 sec to initiate the reaction, followed by 15 cycles of 98° C. for 10 sec, 60° C. for 45 sec, and 72° C. for 16 minutes 30 seconds, and a final extension at 65° C. for 5 min. To check the results, 5 μl PCR product was visualized on 0.4% agarose gel (
DNA templates amplified from full-length PCR were purified using conventional phenol/chloroform extraction followed by Ethanol precipitation in the presence of 3M Sodium Acetate prior to RNA work. RNA transcripts was in vitro synthesized using the HiScribe T7 Transcription Kit (New England Biolabs) according to the manufacturer's instruction with some modifications. A 20 μl reaction was set up by adding 500 ng DNA template and 2.4 μl 50 mM GTP (cap analog-to-GTP ratio is 1:1). The reaction was incubated at 37° C. for 3 hr. Then RNA was precipitated and purified by Lithium Chloride precipitation and washed once with 70% Ethanol. The N gene DNA template was also prepared by PCR from cDNA using specific forward primer (2320-N-F: GAAtaatacgactcactataggGACGTTCGTGTTGTTTTAGATTTCATCTAAACG (SEQ ID NO:162), the lowercase sequence represents T7 promoter; the underlined sequence represents the 5′ NTR upstream of the N gene ORF) and reverse primer (2130-N-R, tttt GTCATTCTCCTAAGAAGCTATTAAAATCACATGG (SEQ ID NO:163)).
Vero E6 cells were obtained from ATTC (CRL-1586) and maintained in DMEM high glucose supplemented with 10% FBS. To transfect viral RNA, 10 μg of purified full length genome RNA transcripts, together with 5 ug of capped WA1-N mRNA, were electroporated into Vero E6 cells using the Maxcyte ATX system according manufacturer's instructions. Briefly, 3-4×106 Vero E6 cells were once washed in Maxcyte electroporation buffer and resuspended in 100 μl of the same. The cell suspension was mixed gently with the RNA sample, and the RNA/cell mixture transferred to Maxcyte OC-100 processing assemblies. Electroporation was performed using the pre-programmed Vero cell electroporation protocol. After 30 minutes recovery of the transfected cells at 37 C/5% CO2, cells were resuspended in warm DMEM/10% FBS and distributed among three T25 flasks at various seeding densities (½, ⅓, ⅙ of the total cells). Transfected cells were incubated at 37° C./5% CO2 for 6 days or until CPE appeared. Infection medium was collected on days 2, 4, and 6, with completely media change at day 2 and day 4 (DMEM/5% FBS). The generated viruses were detectable by plaque assay as early as 2 days post transfection, with peak virus generation between days 4-6.
Serial 10-fold dilutions were prepared in DMEM/2% FBS. 0.5 ml of each dilution were added to 12-wells of Vero E6 cells that were 80% confluent. After 1 hour incubation at 37° C., the inoculum was removed, and 2 ml of semisolid overlay was added per well, containing 1×DMEM, 0.3% Gum Tragacanth, 2% FBS and 1× Penicillin/Streptomycin. After 3 or 4 day incubation at 37° C./5% CO2 the overlay was removed, wells were rinsed gently with PBS, followed by fixation and staining with Crystal Violet.
RNA obtained from In vitro transcription was used to transfect Vero E6 cells with wt WA1 and CDX-005 and recover live virus that was titrated in Vero E6 cells. After incubation for 3 days, plaque assays were stained.
Vero cells (WHO 10-87) were grown for 3 days in 12 well plates containing 1 ml DMEM with 5% fetal bovine serum (FBS) until they reached near confluency. Prior to infection, spent cell culture medium was replaced with 0.5 ml fresh DMEM containing 1% FBS and 30 PFU of the indicated viruses (0.0001 MOI). After a 1-hour incubation at 33° C. or 37° C./5% CO2, inoculum was discarded, cell monolayers were washed once with 1 ml Dulbecco's PBS, followed by addition of 1 ml DMEM containing 1% FBS. Infected cells were incubated at 33° C. or 37° C. for 0, 6, 24, 48, or 72 hrs. At the indicated timepoints, cells and supernatants were collected (one well per time point), frozen once at −80 C and thawed. Infectious virus titers in the lysates were determined by plaque assay on Vero E6 at 37° C.
Generation of individual genome fragments 1-19 and the whole genomic DNA generated by overlapping PCR went well, with clear bands visible on 0.4% agarose gels (
In vitro transcription produced RNA used to transfect Vero E6 cells with S-WWW (WT) and S-WWD and recover live virus that was titrated in Vero E6 cells. After incubation for 3 days, the plaque assays were stained and we observed smaller plaques observed in the partially spike-deoptimized S-WWD candidate (
The CDX-005 pre-master virus seed (preMVS) was developed as follows: RNA of SARS-COV-2 BetaCoV/USA/WA1/2020 (GenBank: MN985325.1) was extracted from infected, characterized Vero E6 cells (ATCC CRL-1586 Lot #70010177) and converted to 19 overlapping DNA fragments by RT-PCR using commercially available reagents and kits. Overlapping PCR was used to stitch together 19 1.8 kb wt genome fragments along with one deoptimized Spike gene cassette. Specifically, 1,272 nucleotides of the Spike ORF were human codon pair deoptimized from genome position 24115-25387 resulting in 283 silent mutations changes relative to parental WA1/2020 virus. The resulting full-length cDNA was transcribed in vitro to make full-length viral RNA. Viral recovery was conducted in a new BSL-3 laboratory at Stony Brook University (NY) that was commissioned for the first time in April 2020, with our project being the only project ever to occur in the lab. This viral RNA was then electroporated in characterized Vero E6 cells (Lot #70010177). This yielded CDX-005 virus (
To produce a seed virus (preMVS) suitable for entrance into GMP, the P1 lot was passaged at Codagenix in the our characterized 10-87 WHO Vero cells (Lot: 563173-MCB1, COA and characterization testing) supplemented with qualified 2% fetal bovine serum (FBS) sourced from New Zealand. Resulting virus was clarified by centrifugation, sterile filtered and filled into 2 ml cryovials to yield preMVS (Lot #1-061720-1) with the titer of 5×105 2.6×106 pfu/ml. The preMVS is to be sent to BioReliance (Glasgow, UK) for sterility and mycoplasma testing under BSL3. Furthermore, the Vero culture that produced 1-061720-1 was allowed to grow for additional two-days to full cytopathic effect and then vialed to conduct and for comprehensive, molecular-based adventitious virus testing including simian, human, porcine and bovine viruses at Charles River Laboratories, Malvern, Pa., USA (Table 5).
Master Seed Virus (MSV) is used as Phase I trial material and is cGMP manufactured. CDX-005 will be produced in Vero (ATCC CCL-81) cell line, and is tested using qualified methods and release the product for clinical testing. A formulation for CDX-005 is as currently employed for their intranasal, live-attenuated influenza vaccine in Phase III trials, which was shown to provide stability and safety. A manufacturing process is shown below.
Manufacturing process for CDX-005
The WHO ad hoc Expert Working Group on COVID-19 modelling concluded that both rhesus macaques and ferrets appear to reproduce mild to moderate human disease, but more recent work (Chan, Sia) suggests that Syrian Golden Hamsters may be a more useful model to replicate more severe pulmonary manifestations of this infection.
To investigate the in vivo properties of CDX-005 we turned to Syrian Golden hamsters. A recent survey of current animal models indicates that these hamsters best recapitulate the characteristics of human COVID-19 disease. SARS-CoV-2 replicates efficiently in hamster lungs causing severe pathological lesions following intranasal infection. Viral antigens are present in nasal mucosa, bronchial epithelium, and areas of lung consolidation on Days 2 and 5 after SARS-CoV-2 inoculation, that is cleared on Day 7. Clinical signs include rapid breathing, weight loss, histopathological changes in the lung/airway, intestinal involvement, spleen and lymphoid atrophy, and cytokine activation within one week of virus challenge. Infected hamsters can infect other hamsters housed in the same cage, and neutralizing antibodies (Abs) are detected on Day 14 post-challenge.
The inventors evaluated attenuation of CDX-005 P1 (Lot #1-060820-9-1) compared to WT BetaCoV/USA/WA1/2020 in the hamster model under BSL-3. Further, our challenge with WT 14 days post vaccination will examine the presence/absence of vaccine enhancement.
Thirty-six male hamsters 5-8 weeks old were dosed by intranasal dropper on Day 0 (12 per group) with 0.05 ml of either nominal doses of 5×104 PFU/ml or 5×103 PFU/ml of wild-type WA1/2020 SARS-CoV-2 or 5×104 PFU/ml CDX-005 and followed for 2, 4, 14, and 16 days. Endpoints include cage side observations twice daily, weight daily and temperature twice daily through day 5 and then daily through day 14. Viral load will be measured by qPCR and TCID50 in nasal wash, lung tissue, brain and kidney on Days 2, 4 and 6 post-dosing. The right lung, right kidney and right brain hemisphere will be fixed for histopathologic examination at the same timepoints. On Day 14, the remaining 3 animals dosed with CDX-005 will be challenged with 5×104 PFU/ml wild-type WA1/2020 and nasal wash, lung, brain, and kidney viral load will be measured on Day 16 along with histopathology of the same organs.
Initial data measuring weight loss for 6-days post-inoculation from this study is shown in
Given an approximate hamster weight of 0.1 kg, extrapolation of hamster vaccine dose of 5×104 to a 70 kg human would be equivalent to a dose of 3.5×107, which is higher than likely maximum clinical dose to be tested.
Further, our challenge with WT 14 days post vaccination examines the presence/absence of vaccine enhancement.
Lastly, we appreciate the small sample size; however, the urgent nature of the pandemic combined with BSL-3 space scarcity and this demonstration of marked attenuation should support testing CDX-005 in healthy low-risk adults, who often have asymptomatic infection even with wild-type SARS-CoV-2.
A single 5.0×104 PFU dose of CDX-005 was protective from wild-type challenge 16 days post dose. This pharmacological dose resulted in no distribution to the brain or kidney and limited distribution to the lung with minimal histopathological findings.
Because COVID-19 disease is associated with pulmonary, olfactory and neural dysfunction, we measured viral load in homogenized lungs, olfactory bulbs and brains. Total viral RNA measured by qPCR was near or below the limit of detection in lung, olfactory bulb, and brain on Days 2 and 4 post-inoculation (PI) in CDX-005 inoculated hamsters. In contrast, viral RNA was detected in wt WA1 infected hamsters in all three tissues at both times (
To evaluate the safety of CDX-005, the change in weight in hamsters was monitored for nine days after inoculation. Hamsters inoculated with CDX-005 experienced weight gain during the period, whereas those inoculated with wt WA1 at either dose experienced weight loss (
We also performed histological examinations of the lungs, brain, and kidney. Formalin fixed paraffin sections were stained with hematoxylin and eosin and light microscopic evaluation was conducted by a blinded board-certified veterinary pathologist (N=3 per group). Multiple parameters were scored on a 0-5 pathology rating scale. No changes were noted in brain and kidney sections of hamsters administered wt WA1 or CDX-005. Consistent with the pathological cellular infiltration found in lungs of humans with COVID-19, however, alveolar and/or perivascular or peribronchiolar mixed cell infiltrates, necrosis of the bronchiolar or bronchial epithelium with neutrophilic infiltration into the lumen, and perivascular edema occasionally accompanied by hyperplasia of the bronchiolar or bronchial epithelium was seen in hamsters infected with wt WA1 (
To assess efficacy of CDX-005 as a vaccine, we measured its ability to induce Abs against wt WA1. First, we performed an ELISA to determine IgG titers against SARS-CoV-2 Spike S1 in sera from naïve (mock) hamsters and those inoculated with wt WA1 or CDX-005. Like wt WA1, CDX-005 inoculation induced a strong anti-Spike S1 Abs response (
Finally, we measured the efficacy of CDX-005 in a challenge study. Hamsters were vaccinated intranasally (IN) a single dose of 5×104 PFU CDX-005, and then challenged IN with 5×104 PFU wt WA1 on Day 16 PI. Lungs were harvested on Day 18 (Day 2 post-challenge), and viral loads measured by qRT-PCR. Viral loads of the challenge wt WA1 virus were reduced by more than 10,000-fold in the lungs of CDX-005 vaccinated compared to un-vaccinated hamsters, attesting to the efficacy of the vaccine (
Hamster Studies
The WHO ad hoc Expert Working Group on COVID-19 modelling concluded that both rhesus macaques and ferrets appear to reproduce mild to moderate human disease, but more recent work suggests that Syrian Golden Hamsters may be a more useful model to replicate more severe pulmonary manifestations of this infection.1-3 Hence, Codagenix is currently evaluating attenuation of CDX-005 P1 (Lot #1-060820-9-1) compared to WA1 in the hamster model under BSL-3. All animal studies were performed according to IIT Research Institute IACUC approved protocols.
Thirty-six male Syrian hamsters (Charles Rivers) 5-6 weeks old were utilized on study. For challenge, hamsters were anaesthetized with ketamine (100 mg/kg) and xylazine (10 mg/kg) via intraperitoneal injection and inoculated intranasally on Day 0 (12 per group) with 0.05 ml of either nominal doses of 5×104 PFU/ml or 5×103 PFU/ml of wt WA1 SARS-CoV-2 or 5×104 PFU/ml CDX-005 Animals were observed twice daily and body weights collected daily through Day 8 and then daily from Day 16-Day 18. On Day 16, three CDX-005 inoculated animals were challenged intranasally with 5×104 PFU/ml wt WAL. Six naïve hamsters inoculated with either 5×104 PFU/ml (N=3) or 5×103 PFU/ml (N=3) of wt WA1 served as controls. We combined these two groups as titers overlapped at the two inoculation doses.
These 36 hamsters and an additional 58 (half female/half male) 5-6 weeks old Syrian Golden hamsters (Charles Rivers) were used to study the effects of CDX-005 and wt WA1 inoculation on hamster health as assessed by weight loss. (These additional hamsters are currently being evaluated for other CDX-005 and wt WA1 mediated effects.) In total forty 5×104 PFU CDX-005, forty 5×104 PFU wt WA1, and twelve 5×103 PFU wt WA1 were weighed daily for up to nine days. The N decreased over time for each group as animals were sacrificed for other endpoints on various days PI. The minimum N for 5×104 PFU CDX-005 and 5×104 PFU wt WA1 was 10 and 3 for 5×103 PFU wt WA1.
On days 2, 4, 6 post inoculation three hamsters from each group and on three hamsters on Day 18 from animals challenged on Day 16 were euthanized by intravenous injection of Beuthanasia at 150 mg/kg. The left lung was collected for viral load determination. To measure viral load, lung was homogenized in a 10% w/v in DMEM with antibiotics using a tissue homogenizer (Omni homogenizer) on Day 18 in animals challenged on Day 16 We attempted to perform nasal washes but were unsuccessful in obtaining reproducible washes in these small animals.
Histopathology was performed by a blinded licensed veterinary pathologist. The lungs, brains, and kidneys were formalin fixed, dehydrated, embedded in paraffin, and stained with hematoxylin and eosin. Light microscopic evaluation was conducted by a blinded board-certified veterinary pathologist. Each tissue was graded on multiple pathological parameters and sections scored as 0=Normal, 1=Minimal, 2=Mild, 3=Moderate, 4=Marked, or 5=Severe. Evaluation of all tissues included assessment of cellular infiltration. At least five sections were examined for each organ and scores averaged.
Viral load was measured by qPCR and TCID50 in harvested tissue. To measure viral load, tissue was homogenized in a 10% w/v in DMEM with antibiotics using a bead mill homogenizer (Omni). Infectious virus titers were determined by 50% tissue culture infectious dose (TCID50) assay titrating 10-fold serial dilutions of the lung homogenate on Vero E6 cells and are expressed in log 10 TCID50 units per ml. RNA was extracted from 100 μl of brain homogenate using the Quick-RNA Viral Kit (Zymo Research) according to the manufacturer's protocol. qRT-PCR was performed using the iTaq 1-step universal probe kit (Bio-Rad) using the following PCR cycling conditions: 40 cycles of 15 s at 95° C., 15 s at 60° C. and 20 s at 72° C.
Hamster sera collected at Day 16 PI were heat inactivated for 30′ at 56 C. 50 ul two-fold serial dilutions were performed in DMEM/1% FBS in 96-well U-bottom plates, starting with an initial dilution of 1:5. Approximately 30 PFU of SARS-CoV-2 Washington/1/2020 in 50 ul DMEM/1% FBS was added to the serum dilutions and mixed, bringing the final volume in the neutralization wells to 100 ul, and the total initial serum dilution to 1:10. Dilution plates were incubated for one hour at 37° C./5% CO2.
The cell growth medium on 24-well plates containing confluent monolayers of Vero E6 cells (seeded one day prior in DMEM/5% FBS), was removed, and 150 ul fresh DMEM/1% FBS was added, followed by 100 ul of each neutralization reaction. After one hour virus adsorption at 37° C./5% CO2, 0.75 ml semisolid overlay was added to the 24 well plates for a final concentration of 1×DMEM, 1.75% FBS, 0.3% Gum Tragacanth, 1× Penicillin+Streptomycin, in a total volume of 1 ml. 24 well plates were incubated 48 hours at 37° C. to allow for plaque formation. Plaques were visualized by fixing and staining the cell monolayers with 1% Crystal Violet in 50% Methanol/4% Formaldehyde. The plaque reduction neutralization titer (PRNT)50, 80, 90 was determined as the reciprocal of the last serum dilution that reduced plaque numbers by the pre-defined cutoff (50%, 80%, 90%) relative to the plaque numbers in non-neutralized wells (containing naïve hamster serum). Sera that failed to neutralize at the lowest dilution (1:10) was assigned a titer of 5, and sera that neutralized at the highest tested serum dilution (1:1280) were assigned a titer of ≥1280.
Ninety-six well plates were coated with SARS-CoV-2(2019-nCoV) Spike S1-His (Sino Biological) at 30 ng/well in 50 ng/ml BSA/0.05M Carbonate/Bicarbonate Buffer pH9.6 overnight at 4° C. Plates were blocked with 10% goat serum in PBS 2 hr at 37° C., washed four times with washing buffer (0.1% Tween 20 in PBS) then incubated with a serially diluted serum (1:10 starting dilution and two folds thereafter) in 10% Goat serum/0.05% Tween-20 in PBS and incubated 1 hr at 37° C. Plates were washed four times with washing buffer then incubated with 1:10,000 horseradish peroxidase (HRP) conjugated affinity pure goat anti-Syrian hamster IgG (H & L) (Jackson ImmunoResearch Laboratories, Inc.) for 1 hr at 37° C. After the incubation, the plates were washed four times with washing buffer and Thermo Scientific OPD (o-phenylenediamine dihydrochloride) was added for colorimetric reaction. Following 10 min of incubation in the dark at 25° C., the reaction was stopped by adding 50 ml 2.5M sulfuric acid solution and the resultant absorbance was read on a microplate reader at 490 nm. Relative IgG levels among different groups were reported and compared as the log of the dilution at which the intensity of OPD colorimetric reaction product reached five time above the background (no serum) control intensity.
CDX-005 contains 283 and CDX-007 contains 149 silent mutations in the Spike gene relative to wt WA1 virus. The resulting full-length wt WA1 and deoptimized cDNAs were transcribed in vitro to make full-length viral RNA that was electroporated into Vero E6 cells. Transfected cells were incubated for 6 days or until CPE appeared. Infection medium was collected on Days 2, 4, and 6. Virus titer was determined by plaque assay on Vero E6 cells. Plaques were visible as early as Day 2 post transfection, with peak virus generation on Days 4-6. Though plaques formed by CDX-005 and CDX-007 are smaller than wt, both grow robustly in Vero E6 cells, indicating their suitability for scale-up manufacturing. Thus, as with our other SAVE vaccines, we were able to rapidly generate multiple vaccine candidates with different degrees of attenuation.
Since CDX-005 is more deoptimized and more attenuated than CDX-007 but grows robustly enough to be produced at scale, to maximize in vivo safety, we selected it for further study. In CDX-005, 1,272 nucleotides of the Spike ORF were codon pair deoptimized for human cells, yielding 283 silent mutations. The polybasic furin cleavage site was removed from the Spike protein for added attenuation and safety.
We performed growth optimization studies for CDX-005 in our GMP characterized animal origin-free (AOF) Vero (WHO-10-87) cells so that we can begin large scale vaccine production by Q4 2020. Growth at 33° C. results in higher titers for both CDX-005 and wt WA1 than at 37° C. Virus peaks before the cytopathic effect (CPE) is observed, with 80-90% of virus being cell associated at the peak. Though the kinetics differ, similar virus titers can be achieved at 0.01 MOI and 0.0001 MOI.
We also investigated optimal conditions for virus harvest. Vero WHO 10-87 cells were grown DMEM with 5% fetal bovine serum (FBS) at 37° C./5% CO2. At 48 h post-infection with CDX-005 in culture at 33° C., cells and supernatant were harvested using the schemes described in
The data demonstrate that 48 hr after 0.01 MOI infection at 33° C. most CDX-005 is cell-associated (˜80-90%) but that virus recovery from Vero cells is straight-forward. Hypotonic lysis is an effective means to harvest CDX-005, and the broad lysis window suggests this method will be feasible in scaled batches where some flexibility may be beneficial.
Freeze/thaw lysis is also effective and FBS is neither necessary nor beneficial. This is desirable both because FBS during infection can lead to Vero cell overgrowth, reducing virus yield, and the FDA prefers serum-free production. Also of note, CDX-005 appears to be stable when frozen in plain DMEM as FBS provided little or no stabilization at least after two freeze/thaw cycles. Thus, with optimal timing of harvest, whether grown at 33° C. or 37° C., crude bulk titers of 2-3×107 PFU/ml of CDX-005 are routinely observed, or about 106 PFU/cm2 growth surface area.
Based on these studies we are currently growing CDX-005 by inoculating Vero (WHO-10-87) cells with 0.01 MOI at 33° C. We have selected and tested a vaccine formulation of DMEM with 5% sucrose and 5% glycine for our first-in-human studies in the UK. In this formulation, CDX-005 is stable for at least three freeze-thaw cycles and one month at −80° C. (the longest tested storage duration thus far).
Finally, as a first step in assessing the genomic stability of CDX-005, we have sequenced viral passages 1-6 after propagating the virus on Vero (WHO 10-87) cells. The data indicate that the virus is extremely stable. Sequencing of passage 6 revealed no subpopulations. We have grown and harvested nine passages and are currently sequencing passage 9. We will have completed harvesting and sequencing of passage 10 by the beginning of the work described here.
Th1/Th2: SARS-CoV-2-specific T cells are present relatively early and increase over time in infected individuals. The strongest T-cell responses appear to be directed to the Spike (S) surface glycoprotein, and SARS-CoV-2-specific T cells predominantly produce effector and Th1 cytokines, although Th2 and Th17 cytokines are detected. It has been suggested that Th1 and T-cytotoxic lymphocytes are the immune cells most affected by SARS-CoV-2, and that T-cell responses and the Th1/Th2 balance may in part dictate the severity of COVID-19. In older individuals who commonly have dampened Th1 responses, the immune system may be forced into a Th2 response to counteract the viral load, producing all the negative effects of the Th2 response, seriously aggravating the clinical picture. Interestingly, T cell responses to SARS-CoV-2 also differ in adults and children. Adults, but not children who developed COVID-19 show increased numbers of activated CD4 and CD8 cells expressing D related antigen (DR) and plasma IL-12, IL-10, and CXCL9 levels. These suggest prominent Th1 polarization of immune response against SARS-CoV-2 in infected adults as compared with children. Because CDX-005 is a live virus, which unlike other vaccine classes can boost immune response by inducing T cell responses, studying the Th1/Th2 balance as directed by the FDA is particularly relevant.
As specified by the FDA, we will measure mRNA levels in lung tissue for Th1/Th2 factors interferon gamma (IFNγ), interleukin 12 (IL-12), tumor necrosis factor alpha (TNFβ), IL4, IL10, and transforming growth factor beta (TGFβ). Tissue homogenates will be analyzed by qPCR using published hamster-specific primers and conditions. The assays will be performed at Bioqual using standard in-house procedures.
We expect that both wt WA1 and CDX-005 inoculation will induce a predominantly Th1 response since these will be young (but not juvenile animals). We expect that there will be a different response to initial inoculation compared to challenge and that those differences may provide insight into the nature of the immune response engendered by SARS-CoV-2.
Efficacy: We will perform a standard challenge study to assess late passage CDX-005 vaccine efficacy. Hamsters inoculated with either 5×104 PFU CDX-005 or Vehicle will be challenged with ˜1.0×105 TCID50 wt WA1 on Day 27. Day 27 was selected based on other hamster studies and our own data. Three mock challenged animals will be included as contemporaneous negative controls, one for each of the three time points at which we will sacrifice challenged animals. Again the choice of sacrifice at Day 2 and 4 post-challenge is based on published and our own data. We have included a later time point at the suggestion of the FDA and to better understand SARS-CoV-2 induced immune responses. Analysis of hamster serum and tissue will include the same analyses using the same protocols as for hamsters that received only inoculum.
We expect that late passage CDX-005 inoculation will provide protection against challenge similar to that of early passage virus. Data suggest that CDX-005 vaccination is highly effective, reducing Day 2 qPCR lung titers by at least 5,000-fold. A more than 100-fold loss of efficacy or significant differences in measures of safety (i.e., biodistribution, histopathology, or attenuation) of late passage relative to early passage CDX-005 would warrant further examination. We would inform the FDA and work with them to decide on next steps.
As a prelude to moving CDX-005 to first-in-human clinical trials, we examined response of non-human primates to the vaccine. We have inoculated, intranasally, fifteen African green monkeys, six with 106 PFU wt WA1, six with 106 PFU CDX-005, and three with Dulbecco's PBS. Our findings show that while viral titers in lavage fluid of wt WA1 and CDX-005 inoculated animals were similar at Day 4 PI, viral titers remained high in wt WA1 but plummeted to undetectable in CDX-005 inoculated monkeys. These data further demonstrate CDX-005's potential as a SARS-CoV-2 vaccine.
COVI-VAC is a live, attenuated vaccine having CDX-005 for prevention of COVID-19. The attenuated virus, carries 283 designed silent mutations with a human codon-pair deoptimized nucleic acid sequence in the gene encoding the viral spike protein and deletion of the furin cleavage site in the spike gene. In addition, it carries 2 silent and 5 nonsilent mutations that were selected for during the virus recovery process in Vero cells.
Primary Study Objective is to assess the safety and tolerability of COVI-VAC at 1 or 2 doses of approximately 5×104, 5×105, and 5×106 plaque-forming units (PFU) administered by nose drops. The Endpoints are: reactogenicity events for 14 days after each dose; adverse events (AEs) from Day 1 to Day 57; medically attended AEs (MAAEs), new-onset chronic illnesses (NCIs), serious AEs (SAEs) from Day 1 to Day 400.
Secondary Study Objective is to assess the humoral immunogenicity of COVI-VAC administered by nose drops. Endpoints are: immunoglobulin G (IgG) titre measured by enzyme-linked immunosorbent assay (ELISA) in serum collected on Days 1, 15, 29, 43, 57, 120, 210, and 400; neutralizing antibody level measured by microneutralization assay in serum collected on Days 1, 15, 29, 43, 57, 120, 210, and 400.
Exploratory objectives and endpoints include:
This study is a Phase 1, randomised, double-blind, placebo-controlled, dose-escalation, clinical trial to evaluate the safety and immunogenicity of COVI-VAC in healthy adults aged 18 to 30 years. Potential subjects will be screened using the site's generic screening process, and individuals who pass this screen will be admitted to the Quarantine Unit 1 to 2 days before dosing (Day −2/−1) and provide informed consent. They will then be screened for eligibility for this study before randomisation on Day 1. Approximately 48 subjects who meet all study inclusion and no exclusion criteria will be enrolled in 3 escalating-dose cohorts and randomised within each cohort in a 3:3:2 ratio to receive 2 doses of COVI-VAC/placebo (normal saline) as shown in the table below.
Cohort 1 will include a sentinel group of 3 subjects (2 active, 1 placebo). The Safety Review Committee (SRC) will review blinded safety data for these 3 subjects through Day 8 before the remaining subject in Cohort 1 are dosed.
Subjects will remain in the Quarantine Unit until 14 days after Dose 1 (and Dose 2 if administered in the inpatient setting) and will be discharged on Day 15 (and 43, if applicable) unless the subject is experiencing clinically significant symptoms or evidence of ongoing viral infection or the Quarantine Unit has been informed by the laboratory unit that the subject is shedding vaccine virus at a level with more than a low transmission risk as documented in the Risk Management Plan (on the basis of Day 14/42 nasopharyngeal swab sample). These subjects will continue to be confined in the Quarantine Unit until qPCR assay results are consistent with low transmission risk (samples will be collected twice daily).
The SRC will also review blinded safety data through Day 15 and blinded nasopharyngeal swab shedding data through at least Day 8 to determine if the cohort of subjects will be confined in the Quarantine Unit for 14 days after Dose 2 or will be discharged on Day 29 and subsequently seen as outpatients. If subjects are to be seen as outpatients, the SRC will also decide using these data on which 2 days in the first week after Dose 2 the subjects will return to the unit for visits. If subjects are to be seen as inpatients, the SRC will also determine the frequency of nasopharyngeal swab sample collection (no greater than twice daily).
Each subject will record reactogenicity (local events, systemic events, and temperature) in a diary daily for 14 days after the COVI-VAC/placebo dose.
All AEs and concomitant medications will be recorded from signing of the informed consent form (ICF) to Day 57. Thereafter to the end of the study (Day 400), only MAAEs, NCIs, SAEs, immunosuppressive medications, blood products, and vaccines will be recorded. Samples for safety laboratory tests (haematology, biochemistry, coagulation, urinalysis) will be collected before Dose 1 and on Days 8, 36, and 57. A complete physical examination will be performed on Day 2/1, and targeted and symptom-driven physical examinations will be performed predose on Day 1 and Day 29; 2 hours after each dose; on Days 2/30, 4/32, 8/36, and 15/43 while in the Quarantine Unit, and at each outpatient visit in the Dosing Period. Peak expiratory flow (PEF) and vital signs (including oxygen saturation) will be measured predose on Days 1 and 29; 2 hours after each dose; on Days 2/30, 4/32, 8/36, and 15/43 while in the Quarantine Unit; and at each outpatient visit in the Dosing Period. An electrocardiogram (ECG) will be performed before Dose 1 and on Days 2, 8 and 57. A chest X-ray will be performed 14 to 22 days after Dose 1 (between Day 15 and Day 22).
A serum sample will be collected from each subject for evaluation of IgG titre measured by ELISA and neutralizing antibody level measured by microneutralization predose on Days 1 and 29 and on Days 15, 43, 57, 120, 210, and 400. A whole blood sample will be collected from each subject and processed to isolate PBMCs for evaluation of T-cell response by IFN-γ ELISpot predose on Days 1 and 29 and on Days 8 and 36.
A nasopharyngeal swab sample will be collected from each subject twice daily (frequency may be reduced after Dose 2) while in the Quarantine Unit (except postdose only on Day 1, predose only on Day 29 if subjects are admitted on an outpatient basis for Dose 2, and 1 sample only on Day 15/43) and at outpatient visits as determined after Dose 2 to measure concentration of vaccine virus for assessment of shedding by qPCR assay. Once a negative result for an individual subject is obtained, later samples for that subject may not be tested. Samples with evidence of vaccine virus shedding will be retained for potential viral sequencing. A swab sample from stool will be collected on Days 4 or 5 and 14 or 15 to measure vaccine virus for titre.
A nasal wick sample will be collected from each subject for measurement of IgA by ELISA for evaluation of mucosal immune response predose on Days 1 and 29 and on Days 15, 43, and 57.
If a subject experiences acute symptoms compatible with viral respiratory infection, nasopharyngeal swab samples will be collected for multiplex PCR respiratory panel (including SARS-CoV-2).
Any sample positive for SARS-CoV-2 will be retained for analysis to determine if it is wild-type SARS-CoV-2 or vaccine virus.
Each subject will participate in the study for approximately 13 months, including the screening period. The end of the study is defined as the date of the last visit of the last subject participating in the study. The expected duration of study conduct is approximately 17 months, assuming 4 months to enroll subjects.
COVI-VAC is administered by nose drops, up to 2 doses at a 28-day interval. The minimum infectious dose for SARS-CoV-2 is unknown, but animal models result in reproducible infection at doses of 104 to 106 PFU. Weight-based extrapolation of the COVI-VAC dose that was well tolerated in the Syrian hamster model results in a dose of approximately 3.5×107 PFU in a 70 kg human. The dose levels chosen for this study are likely to be both well tolerated and sufficient for evaluation of the activity of COVI-VAC.
Safety: The number (percentage) of subjects with AEs (including MAAEs, NCIs, and SAEs) from Day 1 to Day 57 will be summarised for each Medical Dictionary for Regulatory Activities (MedDRA) system organ class and preferred term and by group. The number (percentage) of subjects with MAAEs, with NCIs, and with SAEs from Day 1 to Day 400 will be summarised in a similar fashion. The number (percentage) of subjects with AEs by severity and by relationship to investigational medicinal product (IMP) will also be summarised. Listings of AEs, MAAEs, NCIs, and SAEs will be provided. The number (percentage) of subjects with local and reactogenicity systemic events after each dose will be summarised by group. Reactogenicity events will also be summarised by severity.
Summary statistics for continuous parameters (safety laboratory tests, PEF, and vital signs) will be presented by group as follows: predose, postdose, and change from predose to postdose assessment. The number and percentage of subjects with postvaccination safety laboratory values or vital sign values recorded as newly abnormal (i.e., an event with an increase in the toxicity grade relative to the baseline value and with a severity grade of moderate or higher) after study vaccination will be tabulated. Shift tables which cross-tabulate the predose and postdose safety laboratory values of each subject by severity grade will be prepared.
Summaries of the number and percentage of subjects with normal, abnormal not clinically significant, and abnormal clinically significant interpretations for physical examinations, ECGs, and chest X-rays will be presented.
Immunogenicity: The primary variables of interest for assessment of humoral immune response to COVI-VAC are IgG titre and neutralizing antibody level. The following measures and their 95% CIs will be summarised by group:
Cellular and mucosal immune response data will be summarised in the same fashion at the relevant sample collection time points.
Shedding: Vaccine virus shedding data from nasopharyngeal and stool swab samples will be summarised by count and percent positive by time point along with median values. The median, interquartile range, minimum, and maximum duration of vaccine virus shedding will be presented by group for the nasopharyngeal swab results.
Respiratory Virus Incidence: Multiplex PCR respiratory panel (including SARS-CoV-2) results from symptomatic subjects and associated symptoms will be listed.
aThe SRC will review blinded safety data (AE, reactogenicity, and safety laboratory data) through Day 15 and nasopharyngeal swab shedding data through at least Day 8 (blinded individual data, day of maximal shedding, and range of duration) for all subjects in each cohort to determine if the cohort of subjects will be confined in the Quarantine Unit for 14 days after Dose 2 or will be discharged on Day 29 and subsequently seen as outpatients. If subjects are to be seen as outpatients, the SRC will also decide using these data on which 2 days in the first week after Dose 2 the subjects will return to the unit for visits.
bThe Day 29 visit may be delayed up to 2 weeks to avoid dosing over major holiday periods and to optimise subject scheduling. If so, the subsequent visits will be shifted accordingly but will retain the original visit numbering system.
cIf a subject prematurely discontinues the study before Day 57, then the procedures listed for Day 57/ET visit should be performed.
dUnless the subject is experiencing clinically significant symptoms or evidence of ongoing viral infection or the Quarantine Unit has been informed by the laboratory unit that the subject is shedding vaccine virus at a level with more than a low transmission risk (on the basis of Day 14/42 nasopharyngeal swab sample). Any subject whose PCR assay results show continued viral shedding at a level with more than a low transmission risk will continue to be confined in the Quarantine Unit until qPCR assay results are consistent with a low transmission risk (samples will be collected twice daily) and any clinically significant symptoms or evidence of ongoing viral infection has resolved.
eScreening procedures - at first admission (Day −2 to Day −1) ONLY
f2 hours postdose
gAfter Dose 1 ONLY. To be performed between Day 15 and Day 22, inclusive.
hDay 2 and Day 8 ONLY
iMeasured before any blood sample collection
jRequired for all women who are not surgically sterilised
kGrade 3 symptoms within 14 days after each dose (Days 1 to 15 and 29 to 43) and symptoms of any grade at other times
1Predose on Day 29 ONLY; if subjects are to be seen as inpatients for Dose 2, the SRC will also determine the frequency of nasopharyngeal swab sample collection (no greater than twice daily).
mDay 4 or 5 ONLY
nDay 14 or 15 ONLY
oDay 1 ONLY
Evaluation of safety is the primary objective for this study. Safety assessments are standard for early-phase clinical trials and are in accordance with FDA's guidance on preventive vaccine clinical trials [FDA 2007]. In addition, because of the inflammatory sequellae and hypercoagulability seen in wild-type infection, safety laboratory studies will also include C-reactive protein, IL-6 and TNF, d-dimer and high sensitivity troponin-T.
Vital sign assessments will include pulse oximetry and peak flow will also be recorded to assess subclinical respiratory impairment.
In addition, a chest X-ray will be performed 2 to 3 weeks after the first dose of CodaVax-COVID/placebo to monitor subjects for subclinical pulmonary inflammation. Evidence is emerging of the utility of chest imaging in early detection of COVID-19. Chest X-ray screening of asymptomatic individuals and symptomatic individuals with low clinical suspicion for COVID-19 immediately after strict local quarantine in Italy showed a high rate of abnormal findings. In a recent meta-analysis of clinical studies evaluating the proportion of positive chest imaging findings in asymptomatic individuals with SARS-COV-2, the authors concluded that asymptomatic cases can have positive chest imaging and that close clinical monitoring of asymptomatic individuals with radiographic findings is necessary because a significant percentage of them develop symptoms.
Binding and neutralizing serum antibodies are the most frequently assessed vaccine biomarkers, but cellular and mucosal immunity may play and equal or even more important role in preventing infection and disease and in reducing the risk of ongoing transmission. In this study serum binding and neutralizing antibodies will be measured as secondary endpoints and mucosal IgA and T-cell response as measured by IFN-γ ELISpot as exploratory endpoints.
Result from the hamster study indicate that carriage of the vaccine virus will be transient. Nasopharyngeal swab samples will be obtained for qPCR to determine how long the vector persists at the site of administration. Data published to date indicate that gastrointestinal shedding starts later and lasts longer than upper airway shedding although it is of unclear significance. Rectal swab samples will be collected in this study for plaque assay to evaluate gastrointestinal shedding of infectious virus.
For purposes of this study, Inclusion Criteria and Exclusion Criteria are set for as follows. Actual criteria for administration to the population at large can differ. These inclusion and exclusion criteria are not to be interpreted as limiting to the claims unless specifically provided for in the claims.
Subjects who meet all of the following criteria may be included in the study:
10. In addition to the contraceptive requirements above, male subjects must agree not to donate sperm for at least 90 days after the last IMP dose.
11. Willingness to participate and comply with all aspects of the study through the entire study period, including all visits to the research unit
12. Provision of written informed consent
Subjects who meet any of the following criteria will be excluded from the study:
Subjects who fail to meet inclusion and exclusion criteria can be rescreened at the discretion of the Investigator, in consultation with the Sponsor, and may participate in the study if they meet inclusion and exclusion criteria at a later date.
Administration of COVI-VAC/placebo will be delayed for any subject who meets any of the following criteria:
Any signs of symptoms that could inhibit the proper administration of the IMP or interpretation of diary data (e.g., temperature ≥38° C., nasal congestion, rhinorrhoea)
Various embodiments of the invention are described above in the Detailed Description. While these descriptions directly describe the above embodiments, it is understood that those skilled in the art may conceive modifications and/or variations to the specific embodiments shown and described herein. Any such modifications or variations that fall within the purview of this description are intended to be included therein as well. Unless specifically noted, it is the intention of the inventors that the words and phrases in the specification and claims be given the ordinary and accustomed meanings to those of ordinary skill in the applicable art(s).
The foregoing description of various embodiments of the invention known to the applicant at this time of filing the application has been presented and is intended for the purposes of illustration and description. The present description is not intended to be exhaustive nor limit the invention to the precise form disclosed and many modifications and variations are possible in the light of the above teachings. The embodiments described serve to explain the principles of the invention and its practical application and to enable others skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out the invention.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.).
As used herein the term “comprising” or “comprises” is used in reference to compositions, methods, and respective component(s) thereof, that are useful to an embodiment, yet open to the inclusion of unspecified elements, whether useful or not. It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). Although the open-ended term “comprising,” as a synonym of terms such as including, containing, or having, is used herein to describe and claim the invention, the present invention, or embodiments thereof, may alternatively be described using alternative terms such as “consisting of” or “consisting essentially of.”
This application includes a claim of priority under 35 U.S.C. § 119(e) to U.S. provisional patent application No. 62/966,750, filed Jan. 28, 2020, No. 63/048,942, filed Jul. 7, 2020, No. 63/079,337, filed Sep. 16, 2020, and No. 63/079,853, filed Sep. 17, 2020, the entirety of which are all hereby incorporated by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US21/15246 | 1/27/2021 | WO |
Number | Date | Country | |
---|---|---|---|
62966750 | Jan 2020 | US | |
63048942 | Jul 2020 | US | |
63079337 | Sep 2020 | US | |
63079853 | Sep 2020 | US |