Patent Application
20220265816
The present application is a continuation application of International Application No. PCT/RU2022/000046, filed Feb. 18, 2022, which claims priority to Russian Patent Application No. 2021104437, filed on Feb. 21, 2021, the contents of both applications are hereby incorporated by reference in their entirety.
This application includes an electronically submitted sequence listing in .txt format. The .txt file contains a sequence listing entitled “110620_00626 SequenceListing.txt” which was created on Apr. 15, 2022 and is 163,230 bytes in size. The sequence listing contained in this .txt file is part of the specification and is hereby incorporated by reference herein in its entirety.
The group of invention relates to biotechnology, immunology and virology. The use of the agents for revaccination of population against the diseases caused by severe acute respiratory syndrome virus SARS-CoV-2.
Coronaviruses is a large virus family, which cause a wide spectrum of diseases in humans and animals. At the end of 2019 the world faced with a novel zoonotic beta-coronavirus SARS-CoV-2, which cause the outbreak of coronavirus infection (COVID-19) in Wuhan (People's Republic of China (PRC)). On Mar. 11, 2020, the World Health Organization described the spread of the disease in the world as a pandemic. As of Feb. 1, 2021, more than 100 million cases of COVID-19 illnesses were recorded, and more than 2 million people died.
The most common symptoms of COVID-19 include fever, dry cough, dyspnea, and fatigue. Sore throat, pain in joints, running nose, and headache occur more rarely. The illness may have mild or severe course. Advanced age and the presence of chronic diseases are the risk factors.
After the illness both cell-mediated and antibody-mediated immune responses are formed. CD8+ and CD4+ T cells specific to SARS-CoV-2 are found in 70% and 100% of COVID-19 convalescents, respectively. S protein of SARS-CoV-2 is the main target for T cells. In addition, T cells specific to M and N coronavirus proteins are found and less numerous T cells specific to nsp3, nsp4, ORF3a and ORF8 of SARS-CoV-2. Immune response is polarized towards Th1 (Grifoni et al. Targets of T Cell Responses to SARS-CoV-2 Coronavirus in Humans with COVID-19 Disease and Unexposed Individuals. Cell. 2020 Jun. 25; 181(7): 1489-1501.e15).
Antibody immune response is mediated by the antibodies targeted primarily to coronavirus surface S protein. It is shown that RBD of S glycoprotein, which is responsible for binding with ACE-2 receptor on human cells is the main target for virus-neutralizing antibodies. Kinetics of the antibody-mediated immune response against SARS-CoV-2 is characterized by sustainable seroconversion (IgM and IgG) within 7 to 14 days after the symptom appearance. IgG titers increase during the first 3 weeks and begin decreasing to week 8 (Adams ER, Ainsworth M, Anand R. Antibody testing for COVID-19: a report from the National COVID Scientific Advisory Panel. medRxiv. 2020). Furthermore, it was demonstrated that IgG titers correlate with the severity of the disease. (Gregory A Poland et al. SARS-CoV-2 immunity: review and applications to phase 3 vaccine candidates. Lancet. 2020 14-20 Nov.; 396(10262): 1595-1606).
Scientific data accumulated so far are indicative of rather short-term natural immunity to COVID-19, which is formed in a subject who experienced the disease (https://www.cdc.gov/coronavirus/2019-ncov/vaccines/facts.html). This is evident from the observed tendencies of decreasing antibody levels and the cases of coronavirus reinfection (Akiko Iwasaki. What reinfections mean for COVID-19. Lancet Infect Dis. 2021 Jan; 21(1): 3-5.)
Vaccination is the most effective method of infectious disease prevention. By present several COVID-19 vaccines have been developed, which are based on various coronavirus antigens.
At present 8 vaccines for COVID-19 prevention are authorized in the world. The clinical study results showed that immunization with these vaccines results in development of both antibody-mediated and cell-mediated immune response against SARS-CoV-2. However, how durable post-vaccinal protective immunity is provided by each type of vaccines is not yet established. In the opinion of experts, it may show interindividual variability and according to various estimates lasts from 1 to 2 years. Such duration determines the need for development of specific agents for COVID prophylaxis to be used in revaccination of humans.
However, the selection of revaccination agents is a challenging task.
In the course of developing the agents for specific prophylaxis intended for revaccination one should keep in mind the effects arising in humans from booster immunization, which have considerable impact on overall structure of antiinfective immunity including protective properties thereof
It is known that the use of vaccines comprising numerous antigens (for instance, inactivated vaccines) leads to formation of immune response against each antigen. However, in this event the immunity level in respect to given antigen is lower compared to vaccines comprising merely this one antigen (effect of immune response dilution). Furthermore, some antigens in the pathogen structure may be non-protective, and formation of T- and B-cell clones in response against such antigens will not contribute to overall protectivity of immunity interfering with formation the cell clones, which are important for protection.
Based on the above one can conclude that vaccines comprising one or more proteins with pronounced protective properties are more promising for revaccination. In this event revaccination will be associated with additional stimulation (boosting) and equally important focusing of the immune response on antigenic determinants of the pathogen, which are most important for the human protection irrespectively of initial immunization.
No agents for revaccination against coronavirus infection are known from the state of the art.
Technical solution disclosed in RF patent No 2731342 (published on Jan. 1,2020) was chosen by the authors of the claimed invention as a prototype. The variants of agent for induction of specific immunity against severe acute respiratory syndrome virus SARS-CoV-2 are known from this patent.
containing component 1, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 26 with E1 and E3 sites deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and also containing a component 2, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 5 with E1 and E3 sites deleted from the genome with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
containing a component 1, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 26 with E1 and E3 sites deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and also containing a component 2, which is an agent in the form of expression vector based on genome of recombinant strain of simian adenovirus serotype 25 with E1 and E3 sites deleted from the genome with integrated expression cassette selected from SEQ ID NO:4, SEQ ID NO:2, SEQ ID NO:3.
containing a component 1, which is an agent in the form of expression vector based on genome of recombinant strain of simian adenovirus serotype 25 with E1 and E3 sites deleted from the genome with integrated expression cassette selected from SEQ ID NO:4, SEQ ID NO:2, SEQ ID NO:3, and also containing a component 2, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 5 with E1 and E3 sites deleted from the genome with the integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
In addition, in this patent the use of indicated variants of agent for induction of specific immunity against severe acute respiratory syndrome virus SARS-CoV-2 is disclosed, including administration of component 1 and component 2 in effective amounts sequentially at a time interval of at least one week.
The disadvantage of this agent is that the use thereof for prolongation of postvaccinal immunity is not described.
Therefore, background of the invention shows a need for developing an agent, which can be used for revaccination against the diseases caused by SARS-CoV-2 virus
Technical problem of the claimed group of invention is development of the agents providing prolongation of postvaccinal immunity against SARS-CoV-2 virus.
Technical result is the creation of safe and efficacious agent providing prolongation of postvaccinal immunity against SARS-CoV-2 virus.
Said technical result is achieved through disclosure of using an agent containing component 1, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 26 with E1 and E3 sites deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and/or containing a component 2, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 5 with E1 and E3 sites deleted from the genome with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3 for revaccination against the diseases caused by severe acute respiratory syndrome virus SARS-CoV-2.
In addition, the use of the agent is disclosed, said agent containing a component 1, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 26 with E1 and E3 sites deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and also containing a component 2, which is an agent in the form of expression vector based on genome of recombinant strain of simian adenovirus serotype 25 with E1 and E3 sites deleted from the genome with integrated expression cassette selected from SEQ ID NO:4, SEQ ID NO:2, SEQ ID NO:3, or containing only component 2 for revaccination against the diseases caused by severe acute respiratory syndrome virus SARS-CoV-2.
In addition, the use of another agent is disclosed, said agent containing a component 1, which is an agent in the form of expression vector based on genome of recombinant strain of simian adenovirus serotype 25 with E1 and E3 sites deleted from the genome with integrated expression cassette selected from SEQ ID NO:4, SEQ ID NO:2, SEQ ID NO:3, and also containing a component 2, which is an agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 5 with E1 and E3 sites deleted from the genome with the integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3 for revaccination against the diseases caused by severe acute respiratory syndrome virus SARS-CoV-2.
Said agent is used in liquid or lyophilized form.
What is more, buffer for the liquid form contains, % by weight:
In addition, reconstituted lyophilized agent contains buffer composed of, % by weight:
In addition, during the use a component 1 and a component 2 are in separate containers.
Illustrates the results of assessment of immunization efficacy in volunteers using a liquid form of the developed agent according to variant 1 through assessment of the percentage of proliferating CD8+ lymphocytes restimulated by S antigen of SARS-CoV-2.
Y-axis—An amount of proliferating cells, %.
X-axis—Days.
●—indicates individual values of each volunteer on Day 0.
—indicates individual values of each volunteer on Day 14.
Δ—indicates individual values of each volunteer on Day 28.
The median value is shown as a black line for each data set. Statistically significant difference between the values obtained on days 0. 14 and 28 is shown by bracket and symbols *, p<0.05; **, p<0.01; ****, p<0.001, using Mann-Whitney test.
Illustrates the results of assessment of immunization efficacy in volunteers using a liquid form of the developed agent according to variant 1 through assessment of the percentage of proliferating CD4+ lymphocytes restimulated by S antigen of SARS-CoV-2.
Y-axis—An amount of proliferating cells, %.
X-axis—Days.
● indicates individual values of each volunteer on Day 0.
—indicates individual values of each volunteer on Day 14.
Δ—indicates individual values of each volunteer on Day 28.
The median value is shown as a black line for each data set. Statistically significant difference between the values obtained on days 0. 14 and 28 is shown by bracket and symbols *, p<0.05; **, p<0.01; ****, p<0.001, using Mann-Whitney test.
Illustrates the results of assessment of immunization efficacy in volunteers using a lyophilized form of the developed agent according to variant 1 through assessment of the percentage of proliferating CD8+ lymphocytes restimulated by S antigen of SARS-CoV-2.
Y-axis—An amount of proliferating cells, %.
X-axis—Days.
●—indicates individual values of each volunteer on Day 0.
—indicates individual values of each volunteer on Day 14.
Δ—indicates individual values of each volunteer on Day 28.
The median value is shown as a black line for each data set. Statistically significant difference between the values obtained on days 0. 14 and 28 is shown by bracket and symbols *, p<0.05; **, p<0.01; ****, p<0.001, using Mann-Whitney test.
Illustrates the results of assessment of immunization efficacy in volunteers using a lyophilized form of the developed agent according to variant 1 through assessment of the percentage of proliferating CD4+ lymphocytes restimulated by S antigen of SARS-CoV-2.
Y-axis—An amount of proliferating cells, %.
X-axis—Days.
●—indicates individual values of each volunteer on Day 0.
—indicates individual values of each volunteer on Day 14.
Δ—indicates individual values of each volunteer on Day 28.
The median value is shown as a black line for each data set. Statistically significant difference between the values obtained on days 0. 14 and 28 is shown by bracket and symbols *, p<0.05; **, p<0.01; ****, p<0.001, using Mann-Whitney test.
Illustrates the fold increase in IFNγ concentration in the culture medium of peripheral blood mononuclear cells of the volunteers, who were immunized with the liquid form of the developed agent according to variant 1, after restimulation with S antigen of SARS-CoV-2 before immunization (Day 0) and on Days 14 and 28 of the study.
Y-axis—Fold increase in interferon-gamma concentration
X-axis—Days.
●—indicates individual values of each volunteer on Day 0.
—indicates individual values of each volunteer on Day 14.
Δ—indicates individual values of each volunteer on Day 28.
The median value is shown as a black line for each data set. Statistically significant difference between the values obtained on days 0. 14 and 28 is shown by bracket and symbols *, p<0.05; **, p<0.01; ****, p<0.001, using Mann-Whitney test.
Illustrates the fold increase in IFNγ concentration in the culture medium of peripheral blood mononuclear cells of the volunteers, who were immunized with the lyophilized form of the developed agent according to variant 1, after restimulation with S antigen of SARS-CoV-2 before immunization (Day 0) and on Days 14 and 28 of the study.
Y-axis—Fold increase in interferon-gamma concentration
X-axis—Days.
●—indicates individual values of each volunteer on Day 0. —indicates individual values of each volunteer on Day 14.
Δ—indicates individual values of each volunteer on Day 28.
The dots show individual values of each volunteer who participated in the study. The median value is shown as a black line for each data set. Statistically significant difference between the values obtained on days 0. 14 and 28 is shown by bracket and symbols *, p<0.05; **, p<0.01; ****, p<0.001, using Mann-Whitney test.
Illustrates the results of assessment of the antibody-mediated immune response against the antigen of SARS-CoV2 in the volunteers, who were immunized with the liquid form of the developed agent according to variant 1.
Y-axis—Titer of IgG against RBD of S glycoprotein of SARS-CoV-2.
X-axis—Days.
—values of each volunteer.
Illustrates the results of assessment of the antibody-mediated immune response against the antigen of SARS-CoV2 in the volunteers, who were immunized with the lyophilized form of the developed agent according to variant 1.
Y-axis—Titer of IgG against RBD of S glycoprotein of SARS-CoV-2.
X-axis—Days.
—values of each volunteer.
The first stage in the development of the agent for inducing specific immunity against severe acute respiratory syndrome virus SARS-CoV-2 was the selection of a vaccine antigen. As a part of this work, the literature search was performed which demonstrated that the coronavirus S protein was the most promising antigen for creating a candidate vaccine. This type I transmembrane glycoprotein is responsible for virus particles binding, fusion and entry into the cells. As was shown, it induces the production of neutralizing antibodies (Liang M et al, SARS patients-derived human recombinant antibodies to S and M proteins efficiently neutralize SARS-coronavirus infectivity. Biomed Environ Sci. 2005 December;18(6):363-74).
The authors developed various variants of the expression cassettes to achieve the most effective induction of immune response against S protein of SARS-CoV-2.
Expression cassette SEQ ID NO:1 comprises CMV promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal. CMV promoter is a promoter of early cytomegalovirus genes, which provides constitutive expression in numerous cell types. However, the strength of expression of the target gene controlled by CMV promoter varies depending on the cell type. In addition, it was shown that the level of transgene expression controlled by CMV promoter decreases with longer cell cultivation time because of inhibition of the gene expression related to DNA methylation [Wang W., Jia YL., Li YC., Jing CQ., Guo X., Shang XF., Zhao CP., Wang T Y. Impact of different promoters, promoter mutation, and an enhancer on recombinant protein expression in CHO cells. //Scientific Reports—2017.—Vol. 8.—P. 10416].
Expression cassette SEQ ID NO:2 comprises CAG promoters, gene encoding S protein of SARS-CoV-2 and polyadenylation signal. CAG-promoter is a synthetic promoter, which switch on the early enhancer of CMV promoter, chicken [3-actin promoter and chimeric intron (chicken β-actin and rabbit β-globin). The experiments show that transcriptional activity of CAG promoter is higher compared to CMV promotor. [Yang C. Q., Li X. Y., Li Q., Fu S. L., Li H., Guo Z. K., Lin J. T., Zhao S. T. Evaluation of three different promoters driving gene expression in developing chicken embryo by using in vivo electroporation. II Genet. Mol. Res.—2014. —Vol. 13. —P. 1270-1277].
Expression cassette SEQ ID NO:3 comprises EF1 promoters, gene encoding S protein of SARS-CoV-2 and polyadenylation signal. EF1 promoter is a promoter of human eukaryotic translation elongation factor 1β (EF-1α). The promoter is constitutively active in the wide range of cell types [PMID: 28557288. The EF-1α promoter maintains high-level transgene expression from episomal vectors in transfected CHO-K1 cells]. Gene EF-α encodes the elongation factor 1α, which is one of the most common proteins in eukaryotic cells and is expressed almost in all cell types of the mammals. This EF-1α is often active in the cells where the viral promoters are not able to express the controlled genes, and in the cells, where the viral promoters are gradually fade away.
Expression cassette SEQ ID NO:4 comprises CMV promoter, gene encoding S protein of SARS-CoV-2, and polyadenylation signal.
Adenovirus-based vector system was selected for effective delivery of the gene encoding S protein of SARS-CoV-2 coronavirus into the human body. Adenoviral vectors provide a number of advantages: they cannot reproduce in the human cells, enter both dividing and nondividing cells, are able to induce cell-mediated and antibody-mediated immune response, and provide high level of the target antigen expression.
The authors developed the variants of the agent containing two components, which are based on different adenovirus serotypes. In this event the immune response against the vector part of adenovirus, which can develop after administration of the first component of the agent, in future is not boosted and does not affect the generation of antigen-specific immune response against vaccine antigen.
Furthermore, the developed agents expand armamentarium of the agents for inducing the immune response against SARS-CoV-2 coronavirus, and this will provide overcoming the difficulties arisen from the presence of preexisting immune response against some adenovirus serotypes in some part of population.
Thus, the efforts resulted in development of the following agent variants.
Obtaining of expression vector containing genome of recombinant strain of human adenovirus serotype 26.
At Stage 1 the authors developed the design of plasmid construct pAd26-Ends, which carries two sites homologous to genome of human adenovirus serotype 26 (two homology arms) and ampicillin resistance gene. One homology arm is a beginning of human adenovirus serotype 26 (from the left inverted terminal repeat to E1 site) and the viral genome sequence including pIX protein. The second homology arm contains the nucleotide sequence from ORF3 of E4 site to the end of genome. pAd26-Ends construct was synthesized by ZAO “Eurogene” (Moscow).
DNA of human adenovirus serotype 26 isolated from the virions was mixed with pAd26-Ends construct. Homologous recombination between pAd26-Ends and viral DNA resulted in plasmid pAd26-d1E1, which carries the genome of human adenovirus serotype 26 with E1 site deleted.
Then in the obtained plasmid pAd26-d1E1 the sequence containing open reading frame 6 (ORF6-Ad26) was replaced with analogous sequence from the human adenovirus serotype 5 using the conventional cloning methods, to enable effective replication of human adenovirus serotype 26 in the cell culture HEK293. This resulted in plasmid pAd26-d1E1-ORF6-Ad5.
Then E3 site of the adenovirus genome (about 3321 b.p. between pIII gene and U-exon) was deleted from the constructed plasmid pAd26-d1E1-ORF6-Ad5 using conventional genetic engineering methods to increase the vector packing capacity. This resulted in recombinant vector pAd26-only-null based on genome of recombinant strain of human adenovirus serotype 26 containing open reading frame ORF6 of human adenovirus serotype 5 and deleted E1 and E3 sites of the genome. SEQ ID NO:5 was used as a maternal sequence of human adenovirus serotype 26.
In addition, the authors developed several designs of the expression cassette:
expression cassette SEQ ID NO:1 comprises CMV promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal;
expression cassette SEQ ID NO:2 comprises CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal;
expression cassette SEQ ID NO:3 comprises EF1 promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal.
On the basis of plasmid construct pAd26-Ends the constructs pArms-26-CMV-S-CoV2, pArms-26-CAG-S-CoV2, pArms-26-EF1-S-CoV2, containing expression cassettes SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3, respectively, and also bearing homology arms of the genome of human adenovirus serotype 26 were obtained using the genetic engineering methods. Then the constructs pArms-26-CMV-S-CoV2, pArms-26-CAG-S-CoV2, pArms-26-EF1-S-CoV2 were linearized at the unique hydrolysis site between the homology arms, each plasmid was mixed with recombinant vector pAd26-only-null. Homologous recombination resulted in plasmids pAd26-only-CMV-S-CoV2, pAd26-only-CAG-S-CoV2, pAd26-only-EF1-S-CoV2, carrying the genome of recombinant strain of human adenovirus serotype 26 containing open reading frame ORF6 of human adenovirus serotype 5 and deleted E1 and E3 sites of the genome, with expression cassette SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3, respectively.
At Stage 4 the plasmids pAd26-only-CMV-S-CoV2, pAd26-only-CAG-S-CoV2, pAd26-only-EF1-S-CoV2 were hydrolyzed with specific restriction endonucleases to remove the vector part. The obtained DNA products were used for transfection of the cell culture HEK293.
Thus, the expression vector was obtained, containing the genome of recombinant strain of human adenovirus serotype 26 with E1 and E3 sites deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
Obtaining of immunobiological agent in the form of expression vector based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
At this stage of the work the expression vectors obtained in Example 1 were purified using anion exchange and exclusion chromatography. Resultant suspension contained adenovirus particles in the buffer for liquid form of the agent or in the buffer for lyophilized form of the agent.
Thus, the following immunobiological agents based on genome of recombinant strain of human adenovirus serotype 26, with E1 and E3 sites deleted from the genome, and the site ORF6-Ad26 substituted for ORF6-Ad5 were obtained:
1. Immunobiological agent based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:1 (Ad26-CMV-S-CoV2) in the buffer for liquid form of the agent.
2. Immunobiological agent based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:1 (Ad26-CMV-S-CoV2) in the buffer for lyophilized form of the agent.
3. Immunobiological agent based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with expression cassette containing CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:2 (Ad26-CAG-S-CoV2) in the buffer for liquid form of the agent.
4. Immunobiological agent based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome and the site ORF6-Ad26 is substituted for ORF6-Ad5 with expression cassette containing CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:2 (Ad26-CAG-S-CoV2) in the buffer for lyophilized form of the agent.
5. Immunobiological agent based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome and the site ORF6-Ad26 is substituted for ORF6-Ad5 with expression cassette containing EF1 promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:3 (Ad26-EF1-S-CoV2) in the buffer for liquid form of the agent.
6. Immunobiological agent based on genome of recombinant strain of human adenovirus serotype 26, in which E1 and E3 sites are deleted from the genome, and the site ORF6-Ad26 is substituted for ORF6-Ad5 with expression cassette containing EF1 promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:3 (Ad26-EF1-S-CoV2) in the buffer for lyophilized form of the agent.
Each of provided immunobiological agents is a component 1 in variant 1 and in variant 2 of the developed agent.
Obtaining of expression vector containing the genome of recombinant strain of simian adenovirus serotype 25.
At Stage 1 the design of plasmid construct pSim25-Ends carrying two sites homologous to the genome of simian adenovirus serotype 25 (two homology arms) was developed. One homology arm is a beginning of simian adenovirus serotype 25 (from the left inverted terminal repeat to E1 site) and the sequence from the end of E1 site to pIVa2 protein. The second homology arm contains the end nucleotide sequence of adenovirus genome including right inverted terminal repeat. pSim25-Ends construct was synthesized by ZAO “Eurogene” (Moscow).
DNA of simian adenovirus serotype 25 isolated from the virions was mixed with pSim25-Ends. Homologous recombination between pSim25-Ends and viral DNA resulted in plasmid pSim25-d1E1, which carries the genome of simian adenovirus serotype 25 with E1 site deleted.
Then from the constructed plasmid pSim25-d1E1 E3 site of adenovirus genome (3921 b.p. from the beginning of gene 12.5K to gene 14.7K) was deleted using conventional genetic engineering methods to increase the vector packing capacity. This resulted in plasmid construct pSim25-null encoding the full-length genome of simian adenovirus serotype 25 with deleted E1 an E3 sites of the genome. SEQ ID NO:6 was used as a maternal sequence of simian adenovirus serotype 25.
In addition, the authors developed several designs of the expression cassette:
expression cassette SEQ ID NO:4 comprises CMV promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal;
expression cassette SEQ ID NO:2 comprises CAG promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal;
expression cassette SEQ ID NO:3 comprises EF1 promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal.
On the basis of plasmid construct pSim25-Ends the constructs pArms-Sim25-CMV-S-CoV2, pArms-Sim25-CAG-S-CoV2, pArms-Sim25-EF1-S-CoV2, containing expression cassettes SEQ ID NO:4, SEQ ID NO:2 or SEQ ID NO:3, respectively, and also bearing homology arms of the genome of simian adenovirus serotype 25 were obtained using the genetic engineering methods. Then the constructs pArms-Sim25-CMV-S-CoV2, pArms-Sim25-CAG-S-CoV2, pArms-Sim25-EF1-S-CoV2 were linearized at the unique hydrolysis site between the homology arms, each plasmid was mixed with recombinant vector pSim25-null. Homologous recombination resulted in recombinant plasmid vectors pSim25-CMV-S-CoV2, pSim25-CAG-S-CoV2, pSim25-EF1-S-CoV2, containing full-length genome of simian adenovirus serotype 25 with E1 and E3 sites deleted, and expression cassette SEQ ID NO:4, SEQ ID NO:2 or SEQ ID NO:3, respectively.
At Stage 3 the plasmids pSim25-CMV-S-CoV2, pSim25-CAG-S-CoV2, pSim25-EF1-S-CoV2 were hydrolyzed with specific restriction endonuclease to remove the vector part. The obtained DNA products were used for transfection of the cell culture HEK293. Resultant material was used for accumulation of recombinant adenoviruses in preparative amount.
The work resulted in obtaining the human adenoviruses serotype 25, containng the gene encoding S protein of SARS-CoV-2: simAd25-CMV-S-CoV2 (containing expression cassette SEQ ID NO:4), simAd25-CAG-S-CoV2 (containing expression cassette SEQ ID NO:2), simAd25-EF1-S-CoV2 (containing expression cassette SEQ ID NO:3).
Thus, the expression vector was obtained, containing the genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, and with integrated expression cassette selected from SEQ ID NO:4, SEQ ID NO:2, SEQ ID NO:3.
Obtaining of immunobiological agent in the form of expression vector based on the genome of recombinant strain of simian adenovirus serotype 25, in which E 1 and E3 sites are deleted from the genome and with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
At this stage of the work the expression vectors obtained in Example 3 were purified using anion exchange and exclusion chromatography. Resultant suspension contained adenovirus particles in the buffer for liquid form of the agent HJIH in the buffer for lyophilized form of the agent.
Thus, the following immunobiological agents based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome were obtained:
1. Immunobiological agent based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:1 (simAd25-CMV-S-CoV2) in the buffer for liquid form of the agent.
2. Immunobiological agent based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:1 (simAd25-CMV-S-CoV2) in the buffer for lyophilized form of the agent.
3. Immunobiological agent based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, with expression cassette containing CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:2 (simAd25-CAG-S-CoV2) in the buffer for liquid form of the agent.
4. Immunobiological agent based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, with expression cassette containing CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:2 (simAd25-CAG-S-CoV2) in the buffer for lyophilized form of the agent.
5. Immunobiological agent based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, with expression cassette containing EF1 promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:3 (simAd25-EF1-S-CoV2) in the buffer for liquid form of the agent.
6. Immunobiological agent based on genome of recombinant strain of simian adenovirus serotype 25, with E1 and E3 sites deleted from the genome, with expression cassette containing EF1 promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:3 (simAd25-EF1-S-CoV2) in the buffer for lyophilized form of the agent.
Each of provided immunobiological agents is a component 2 in variant 1 and a component 1 in variant 3 of the developed agent.
Obtaining of expression vector containing the genome of recombinant strain of human adenovirus serotype 5.
At Stage 1 the design of plasmid construct pAd5-Ends carrying two sites homologous to the genome of human adenovirus serotype 5 (two homology arms) was developed. One homology arm is a beginning of human adenovirus serotype 5 (from the left inverted terminal repeat to E1 site) and the sequence including pIX protein of the viral genome. The second homology arm contains the nucleotide sequence after ORF3 of E4 site to the end of genome. pAd5-Ends construct was synthesized by ZAO “Eurogene” (Moscow).
DNA of human adenovirus serotype 5 isolated from the virions was mixed with pAd5-Ends construct. Homologous recombination between pAdS-Ends and viral DNA resulted in plasmid pAd5-d1E1, which carries the genome of human adenovirus serotype 5 with E1 site deleted.
Then E3 site of the adenovirus genome (about 2685 b.p. from the end of gene 12.5K to the beginning of U-exon sequence) was deleted from the constructed plasmid pAd5-d1E1 using conventional genetic engineering methods to increase the vector packing capacity. This resulted in recombinant plasmid vector pAd5-too-null based on genome of human adenovirus serotype 5 with E1 and E3 deleted from the genome. SEQ ID NO:7 was used as a maternal sequence of human adenovirus serotype 5.
In addition, the authors developed several designs of the expression cassette:
expression cassette SEQ ID NO:1 comprises CMV promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal;
expression cassette SEQ ID NO:2 comprises CAG promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal;
expression cassette SEQ ID NO:3 comprises EF1 promoter, gene encoding S protein of SARS-CoV-2 and polyadenylation signal.
Then on the basis of plasmid construct pAdS-Ends the constructs pArms-Ad5-CMV-S-CoV2, pArms-Ad5-CAG-S-CoV2, pArms-Ad5-EF1-S-CoV2 containing expression cassettes SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3, respectively, and also bearing homology arms of the genome of human adenovirus serotype 5 were obtained using the genetic engineering methods.
Then the constructs pArms-Ad5-CMV-S-CoV2, pArms-Ad5-CAG-S-CoV2, pArms-Ad5-EF1-S-CoV2 were linearized at the unique hydrolysis site between the homology arms, each plasmid was mixed with recombinant vector pAdS-too-null. Homologous recombination resulted in plasmids pAd5-too-CMV-S-CoV2, pAd5-too-GAC-S-CoV2, pAd5-too-EF1-S-CoV2, carrying the genome of recombinant strain of human adenovirus serotype 5 with E1 E3 sites deleted from the genome and expression cassettes SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO: 3, respectively.
At Stage 4 the plasmids pAd5-too-CMV-S-CoV2, pAd5-too-GAC-S-CoV2, pAd5-too-EF1-S-CoV2 were hydrolyzed with specific restriction endonuclease to remove the vector part. The obtained DNA product were used for transfection of the cell culture HEK293. Resultant material was used for accumulation of recombinant adenoviruses in preparative amounts.
The work resulted in obtaining the human adenoviruses serotype 5, containing the gene encoding S protein of SARS-CoV-2: Ad5-CMV-S-CoV2 (containing expression cassette SEQ ID NO:1), Ad5-CAG-S-CoV2 (containing expression cassette SEQ ID NO:2), Ad5-EF1-S-CoV2 (containing expression cassette SEQ ID NO:3).
Thus, the expression vector was obtained, containing the genome of recombinant strain of human adenovirus serotype 5 with E1 and E3 sites deleted from the genome, with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
Obtaining of immunobiological agent in the form of expression vector based on the genome of recombinant strain of human adenovirus serotype 5 with E1 and E3 sites deleted from the genome, with integrated expression cassette selected from SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3.
At this stage of the work the expression vectors obtained in Example 5 were purified using anion exchange and exclusion chromatography. Resultant suspension contained adenovirus particles in the buffer for liquid form of the agent or in the buffer for lyophilized form of the agent.
Thus, the following immunobiological agents based on genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome:
1. Immunobiological agent based on the genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome, with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:1 (Ad5-CMV-S-CoV2) in the buffer for liquid form of the agent.
2. Immunobiological agent based on the genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome, with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:1 (Ad5-CMV-S-CoV2) in the buffer for lyophilized form of the agent.
3. Immunobiological agent based on the genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome, with expression cassette containing CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:2 (Ad5-CAG-S-CoV2) in the buffer for liquid form of the agent.
4. Immunobiological agent based on the genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome, with expression cassette containing CAG promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:2 (Ad5-CAG-S-CoV2) in the buffer for lyophilized form of the agent.
5. Immunobiological agent based on the genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome, with expression cassette containing EF1 promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:3 (Ad5-EF1-S-CoV2) in the buffer for liquid form of the agent.
6. Immunobiological agent based on the genome of recombinant strain of human adenovirus serotype 5, with E1 and E3 sites deleted from the genome, with expression cassette containing EF1 promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, SEQ ID NO:3 (Ad5-EF1-S-CoV2) in the buffer for lyophilized form of the agent.
Each of provided immunobiological agents is a component 1 in variant 1 and in variant 2 of the developed agent.
Each of provided immunobiological agents is a component 2 in variant 1 and in variant 3 of the developed agent.
Preparation of buffer solution.
The developed agent according to the claimed invention comprises two components placed in separate vials. Each component is an immunobiological agent based on recombinant adenovirus with expression cassette in buffer solution.
The authors of the invention elaborated the composition of buffer solution to ensure stability of recombinant adenovirus particles. Said solution includes:
1. Tris(hydroxymethyl)aminomethane (Tris), which is required for maintaining pH of the solution.
2. Sodium chloride, which is added to achieve appropriate ionic strength and osmolarity.
3. Saccharose, which is used as cryoprotector.
4. Magnesium chloride hexahydrate, which is required as the source of bivalent cation.
5. EDTA, which is used as inhibitor of free-radical oxidation.
6. Polysorbate-80, which is used as a surfactant.
7. Ethanol 95%, which is used as inhibitor of free-radical oxidation.
8. Water, which is used as a solvent.
The author of the invention developed 2 variants of buffer solution for liquid form of the agent and for lyophilized form of the agent.
Several variants of experimental groups were obtained for determining the concentration of the compounds in the composition of buffer solution for liquid form of the agent (table 1). One of the components of the agent was added to each of the prepared buffer solutions:
1. Immunobiological agent based on recombinant human adenovirus serotype 26 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal, 1*1011 virus particles.
2. Immunobiological agent based on recombinant human adenovirus serotype 5 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal, 1*1011 virus particles.
3. Immunobiological agent based on recombinant simian adenovirus serotype 25 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal, 1*1011 virus particles.
Thus, the stability of each of adenovirus serotypes in the agent composition was tested. Prepared pharmaceutical products were stored at the temperature −18° C. and −70 ° C. for 3 months, followed by thawing, and the change in recombinant adenovirus titer was assessed.
The results of the experiment showed that the titer of recombinant adenoviruses did not change after the storage in the buffer for liquid form of the agent at the temperature −18° C. and −70° C. for 3 months.
Therefore, the developed buffer solution for liquid form of the agent provides stability of all components of the developed agent in the following ranges of active ingredients (% by weight):
Tris: from 0.1831% by weight to 0.3432% by weight;
Sodium chloride: from 0.3313% by weight to 0.6212% by weight;
Saccharose: from 3,7821% by weight to 7,0915% by weight;
Magnesium chloride hexahydrate: from 0.0154% by weight to 0.0289% by weight;
EDTA: from 0.0029% by weight to 0.0054% by weight;
Polysorbate-80: from 0.0378% by weight to 0.0709% by weight;
Ethanol 95%: from 0.0004% by weight to 0.0007% by weight;
Solvent: balance.
Several variants of experimental groups were obtained for determining the concentration of the compounds in the composition of buffer solution for lyophilized form of the agent (table 2). One of the components of the agent was added to each of the prepared buffer solutions:
1. Immunobiological agent based on recombinant human adenovirus serotype 26 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal, 1*1011 virus particles.
2. Immunobiological agent based on recombinant human adenovirus serotype 5 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2, and polyadenylation signal, 1*1011 virus particles.
3. Immunobiological agent based on recombinant simian adenovirus serotype 25 with expression cassette containing CMV promoter, the gene encoding S protein of SARS-CoV-2 and polyadenylation signal, 1*1011virus particles.
Thus, the stability of each of adenovirus serotypes in the agent composition was tested. Prepared pharmaceutical products were stored at the temperature +2 and +8° C. ° C. for 3 months, followed by thawing, and the change in recombinant adenovirus titer was assessed.
The results of the experiment showed that the titer of recombinant adenoviruses did not change after the storage in the buffer for lyophilized form of the agent at the temperature +2° C. +8° C. for 3 months.
Therefore, the developed buffer solution for lyophilized form of the agent provides stability of all components of the developed agent in the following ranges of active ingredients (% by weight):
Tris: from 0.0180% by weight to 0.0338% by weight;
Sodium chloride: from 0.1044% by weight to 0.1957% by weight;
Saccharose: from 5,4688% by weight to 10.2539% by weight;
Magnesium chloride hexahydrate: from 0.0015% by weight to 0.0028% by weight;
EDTA: from 0.0003% by weight to 0.0005% by weight;
Polysorbate-80: from 0.0037% by weight to 0.0070% by weight;
Solvent: balance.
The study of the developed agent immunogenicity through assessment of cell-mediated immune response against the antigen of SARS-CoV-2 virus in the blood of volunteers at different time intervals after vaccination.
The clinical studies of the develop agent, variant 1, included investigation of the intensity cell-mediated immunity.
40 volunteers participating in the study were immunized with:
1) Liquid form of the developed agent, variant 1: component 1 followed by component 2 within 21 days (component 1: Ad26-CMV-S-CoV2, component 2: Ad5-CMV-S-CoV2), at the dose of 1×1011 virus particles (20 volunteers).
2) Lyophilized form of the developed agent, variant 1: component 1 followed by component 2 within 21 days (component 1: Ad26-CMV-S-CoV2, component 2: Ad5-CMV-S-CoV2), at the dose of 1×1011 virus particles (20 volunteers).
On Day 0 (before the agent administration), Day 14 and Day 28 the blood samples were collected from the volunteers and centrifugated in the ficcol density gradient in order to isolate mononuclear cells. The isolated cells were stained with CFSE fluorescent dye (Invivogen, CIIIA) and added into the plate wells. Then the lymphocytes were restimulated in vitro by addition of coronavirus S protein into the culture medium (up to final protein concentration 1 μg/mL). Intact cells without antigen addition served as a negative control. 72 hours after antigen addition the percentage of proliferating cells was measured, and the culture medium was collected for measuring the interferon gamma level.
The cells were stained with antibodies against T cell marker molecules CD3, CD4, CD8 (anti-CD3 Pe-Cy7 (BD Biosciences, clone SK7), anti-CD4 APC (BD Biosciences, clone SK3), anti-CD8 PerCP-Cy5.5 (BD Biosciences, clone SK1)) to assess the percentage of proliferating cells. Flow cytofluorimeter BD FACS AriaIII (BD Biosciences, USA) was used to identify proliferating (carrying lesser amount of CFSE dye) CD4+ CD8+ T cells in the cell mixture. The result obtained from analysis of the intact cells was subtracted from the result obtained from analysis of the cells restimulated with coronavirus antigen S in order to determine the resultant percentage of proliferating cells in each sample. Final results are shown in
The concentration of interferon gamma (IFNγ) in the culture medium of human blood mononuclear cells was measured within 72 hours after restimulation with coronavirus S protein with the use of Interferon gamma EIA-BEST kit (VECTOR BEST, Russia) in accordance with instruction of manufacturer. The results are shown in
The study results showed that the intensity of cell-mediated immunity induced by consecutive immunization of volunteers with both forms of the agent, variant 1, grew with time elapsed from immunization, as evidenced by median percentage of proliferating CD4+ CD8+ T cells. In both groups maximum values of proliferating CD4+ and CD8+ T cells were observed on Day 28 after immunization. Maximum statistically significant difference in percentages of proliferating CD4+
CD8+ T cells (p<0.001) was observed between Day 0 and Day 28.
One can conclude from the results shown in
Thus, based on the above data one can conclude that immunization with the developed agent induces strong antigen-specific cell-mediated component of antiinfective immunity, which is supported by high statistical significance of the measured parameters before and after immunization.
The study of the developed agent immunogenicity through assessing the titer of antibodies against SARS-CoV-2 antigen in the blood of volunteers at different time intervals after vaccination.
40 volunteers participating in the study were immunized with:
1) Liquid form of the developed agent, variant 1: component 1 followed by component 2 within 21 days (component 1: Ad26-CMV-S-CoV2, component 2: Ad5-CMV-S-CoV2), at the dose of 1×1011 virus particles (20 volunteers).
2) Lyophilized form of the developed agent, variant 1: component 1 followed by component 2 within 21 days (component 1: Ad26-CMV-S-CoV2, component 2: Ad5-CMV-S-CoV2), at the dose of 1×1011 virus particles (20 volunteers).
On Day 14, Day 21 and Day 28 the blood samples were collected, followed by serum separation.
The titer of antibodies against RBD of SARS-CoV-2 S protein was measured with the use of kit SARS-CoV-2-RBD-E1A-Gamaleya in accordance with instruction of manufacturer.
The results of assay of antibody titer against SARS-CoV-2 antigen in serum of volunteers after administration of liquid form of the agent are shown in
The results of assay of antibody titer against SARS-CoV-2 antigen in serum of volunteers after administration of lyophilized form of the agent are shown in
As is evident from the presented data, immunization of volunteers with the developed agent both in liquids and lyophilized form enables to generate strong (statistically significantly differing from the values obtained in non-immunized control group of animals) antibody-mediated immunity, which is characterized by increase in antibody level against S protein of SARS-CoV-2. The growth of intensity of antibody-mediated immune response with increasing time after immunization is observed.
The use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2 after immunization with the model subunit vaccine.
The objective of this study was to assess potential use of the developed agent for revaccination of the animals, which were immunized with the model subunit vaccine.
In this experiment female mice Balb/c with the body weight 18 g were used. At Stage 1 the animals were immunized with the model vaccine containing S protein of SARS-CoV-2 (10 μg/mouse) in phosphate-buffered saline with aluminium hydroxide (100 μg/mouse). Two doses of the vaccine were administered at 21 day interval between the doses. On Day 180 the animals were re-immunized with various variants of the developed agent. In the event of two-component agent: the first component (1010 virus particles/mouse) was administered on Day 180 of the experiment, and the second component (1010 v.p./mouse) was administered on Day 201. In the event of monocomponent agent immunization was carried out on Day 201 of the experiment. Thus, the following experimental and control group of animals were studied:
1) Model vaccine/Ad26-CMV-S-CoV2/Ad5-CMV-S-CoV2
2) Model vaccine/Ad26-CAG-S-CoV2/Ad5-CAG-S-CoV2
3) Model vaccine/Ad26-EF1-S-CoV2/Ad5-EF1-S-CoV2
4) Model vaccine/Ad26-CMV-S-CoV2/simAd25-CMV-S-CoV2
5) Model vaccine/Ad26-CAG-S-CoV2/simAd25-CAG-S-CoV2
6) Model vaccine/Ad26-EF1-S-CoV2/simAd25-EF1-S-CoV2
7) Model vaccine/simAd25-CMV-S-CoV2/Ad5-CMV-S-CoV2
8) Model vaccine/simAd25-CAG-S-CoV2/Ad5-CAG-S-CoV2
9) Model vaccine/simAd25-EF1-S-CoV2/Ad5-EF1-S-CoV2
10) Model vaccine/Ad26-CMV-S-CoV2
11) Model vaccine/Ad26-CAG-S-CoV2
12) Model vaccine/Ad26-EF1-S-CoV2
13) Model vaccine/Ad5-CMV-S-CoV2
14) Model vaccine/Ad5-CAG-S-CoV2
15) Model vaccine/Ad5-EF1-S-CoV2
16) Model vaccine/simAd25-CMV-S-CoV2
17) Model vaccine/simAd25-CAG-S-CoV2
18) Model vaccine/simAd25-EF1-S-CoV2
On Day 21, Day 180, and Day 222 of the experiment the blood from the tail vein was collected followed by serum separation. The titer of anti-SARS-CoV-2 antibodies was determined by enzyme immunoassay (EIA) according to the following protocol:
1) Antigen was adsorbed on the wells of 96-well microtitration plate at temperature +4° C. for 16 hours.
2) In order to preclude non-specific binding, the plate was “locked” with blocking buffer, which was added in each well in amount 100 μL/well. The plate was incubated on shaker at +37° C. for 1 hour.
3) The sera of immunized mice were diluted 100-fold and then a series of 2-fold dilutions was prepared.
4) 50 μL of each diluted serum sample was added into the plate wells.
5) Then the plate was incubated at +37° C. for 1 hour.
6) After the end of incubation the wells were washed with three portions of the phosphate buffer.
7) Then horseradish peroxidase-conjugated secondary antimouse-IgG antibodies were added.
8) Then the plate was incubated at +37° C. for 1 hour.
9) After the end of incubation the wells were washed with three portions of the phosphate buffer.
10) Then tetramethylbenzidine (TMB) solution was added, which is a horseradish substrate and turns into colored compound in the course of reaction. Within 15 minutes sulfuric acid was added to stop the reaction. Then optical density (OD) of solution was measured at wave length 450 nm in each well using spectrophotometer.
The antibody titer was determined as the highest dilution showing the solution optical density significantly greater than that in the negative control group. The results (geometrical means) are shown in table 3.
The presented data demonstrate the development of antibodies in all animals after immunization with model inactivated vaccine; by Day 180 after immunization the antibody titers decrease, however revaccination of the animals with various variants of the developed agent results in manifold increase in blood antibody titer. Thus, the experimental data support the use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2.
The use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2 after immunization with model inactivated vaccine.
The objective of this study was to assess potential use of the developed agent for revaccination of the animals, which were immunized with the model inactivated vaccine.
In this experiment female mice Balb/c with the body weight 18 g were used. At Stage 1 the animals were immunized with the model vaccine containing formalin-inactivated SARS-CoV-2 virus. Two doses of the vaccine were administered at 21 day interval between the doses. On Day 180 the animals were re-immunized with various variants of the developed agent. In the event of two-component agent: the first component (1010 v.p./mouse) was administered on Day 180 of the experiment, and the second component (1010 v.p./mouse) was administered on Day 201. In the event of monocomponent agent immunization was carried out on Day 201 of the experiment. Thus, the following experimental and control group of animals were studied:
On Day 21, Day 180, and Day 222 of the experiment the blood from the tail vein was collected followed by serum separation. The titer of anti-SARS-CoV-2 antibodies was determined by enzyme immunoassay (E1A) according to the following protocol:
The antibody titer was determined as the highest dilution showing the solution optical density significantly greater than that in the negative control group. The results (geometrical means) are shown in table 4.
The presented data demonstrate the development of antibodies in all animals after immunization with model inactivated vaccine; by Day 180 after immunization the antibody titers decrease, however revaccination of the animals with various variants of the developed agent results in manifold increase in blood antibody titer. Thus, the experimental data support the use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2.
The use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2 after immunization with various variants of the developed agent.
The objective of this study was to assess potential use of the developed agent for revaccination of the animals, which were immunized with various variants of the developed agent.
In this experiment female mice Balb/c with the body weight 18 g were used. At Stage 1 the animals were immunized with various monocomponent variants of the developed agent (1010 v.p./mouse). On Day 180 the animals were re-immunized with various two-component variants of the developed agent. (1010 v.p./mouse). The first component (1010 v.p./mouse) was administered on Day 180 of the experiment, and the second component (1010 v.p./mouse) was administered on Day 201. In the event of monocomponent agent immunization was carried out on Day 201 of the experiment. Thus, the following experimental and control group of animals were studied:
On Day 21, Day 180, and Day 222 of the experiment the blood from the tail vein was collected followed by serum separation. The titer of anti-SARS-CoV-2 antibodies was determined by enzyme immunoassay (EIA) according to the following protocol:
The antibody titer was determined as the highest dilution showing the solution optical density significantly greater than that in the negative control group. The results (geometrical means) are shown in table 5.
The presented data demonstrate the development of antibodies in all animals after immunization of mice with monocomponent variants of the developed agent; by Day 180 after immunization the antibody titers decrease, however revaccination of the animals with various variants of the developed agent results in manifold increase in blood antibody titer. Thus, the experimental data support the use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2.
The use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2 after immunization with various variants of the developed agent.
The objective of this study was to assess potential use of the developed agent for revaccination of the animals, which were immunized with various variants of the developed agent.
In this experiment female mice Balb/c with the body weight 18 g were used. At Stage 1 the animals were immunized with variants of the developed two-component agent (1010 v.p./mouse) at 21 day interval. On Day 180 the animals were re-immunized with various monocomponent variants of the developed agent. Thus, the following experimental and control group of animals were studied:
On Day 42, Day 180, and Day 222 of the experiment the blood from the tail vein was collected followed by serum separation. The titer of anti-SARS-CoV-2 antibodies was determined by enzyme immunoassay (EIA) according to the following protocol:
The antibody titer was determined as the highest dilution showing the solution optical density significantly greater than that in the negative control group. The results (geometrical means) are shown in table 6.
The presented data demonstrate the development of antibodies in all animals after immunization of mice with two-component variants of the developed agent; by Day 180 after immunization the antibody titers decrease, however revaccination of the animals with various variants of the developed agent results in manifold increase in blood antibody titer. Thus, the experimental data support the use of the developed agent for prolongation of postvaccinal immunity against SARS-CoV-2.
Thus, the assigned technical problem, specifically, creation of the agents providing prolongation of postvaccinal immunity against SARS-CoV-2 virus, is solved as supported by presented examples.
All presented examples support the efficacy of the agents, which provide efficacious induction of immune response and also prolongation of postvaccinal immunity against SARS-CoV-2 virus and industrial use.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021104437 | Feb 2021 | RU | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/RU2022/000046 | Feb 2022 | US |
| Child | 17722227 | US |
