Hantavirus vaccine

Abstract

Vaccine formulations for inducing protective immune response to Hantaviruses in humans are disclosed. These formulations include an attenuated vaccinia virus vector containing cDNA's encoding Hantavirus nucleocapsid N protein, G1 and G2 glycoproteins. Methods for the use of these formulations also are disclosed.

Description

Infectious febrile diseases with hemorrhagic and renal manifestations have been recognized across the Eurasian land mass for more than 50 years. Seven thousand cases of a "war nephritis" clinically similar to nephorpathia epidemica (NE) were reported among British soldiers stationed in Flanders during World War I. Brown, Lancet i., 316-395 (1916). Nevertheless, these disorders were not given much attention by Western physicians until the early 1950's during the Korean conflict, when over 3000 cases were diagnosed among United Nations forces. Earle, Am. J. Med. 16: 617-709 (1954).

Subsequently, it was recognized that Korean hemorrhagic fever and clinically similar diseases, collectively termed hemorrhagic fever with renal syndrome (HFRS), pose a significant health threat in much of Asia and parts of Europe and Scandinavia. Non-pathogenic infection of rodent populations apparently provides a reservoir for the causative agent. Infection of humans occurs via aerosol of the agent, a Hantavirus of the family Bunyaviridae, from rodent urine, feces and saliva. Mortality rates have decreased from the 10 to 15% seen during the Korean conflict to 5% or less, if improved fluid and electrolyte management and/or renal dialysis are available. Currently, an estimated 50,000-100,00 case occur annually in the Peoples' Republic of China, with mortality rates ranging from 5 to 20%, in various provinces.

A recent randomized, placebo-controlled clinical trial of intravenous ribavirin in HFRS patients presenting within the first six days of clinical symptoms demonstrated a significant reduction in mortality. Huggins et al., J. Infect. Dis. 164: 1119-1127 (1991); Lee and Ahn, J. Korean Soc. Virol. 18: 143-148 (1988). Otherwise, management of all HFRS patients is highly individualized and focused on supportive care.

A Hantavirus vaccine has been approved and is in use in South Korea. Lee and Ahn (1988). This vaccine was developed by serial passage of the virus in brains of suckling pigs, followed by inactivation with formalin. Initial claims reported that two doses of the vaccine, given via a subcutaneous route one month apart, resulted in 100% seroconversion as measured by immunofluorescence. The production of this vaccine, however, was not in compliance with current U.S. Food and Drug Administration guidelines on "Good Manufacturing Practices," and the protective efficacy has not yet been determined. Furthermore, adventitious agents in the product were not rigorously excluded and the animal colony used for the vaccine's development was not pathogen-free. Other vaccines are currently undergoing testing in Japan, North and South Korea and China. Both Korean vaccine trials involved the use of formalin-inactivated, Hantaan virus-infected mouse brain. Suh et al., Virus Information Exchg. Newsl. 6: 131 (1989); Lee and Ahn (1988). The Chinese and Japanese trials involve inactivated, tissue culture-derived Hantavirus preparations. Yu and Zhe, Virus Information Exchg. Newsl. 6: 131 (1989).

"Hantaan" virus, the etiologic agent of Korean hemorrhagic fever, was originally isolated from the Korean striped field mouse. Lee et al., J. Infect. Dis. 137: 298-307 (1978). This serotype is the prototype for the Hantavirus genus. Schmaljohn and Dalrymple, Virology 131: 482-491 (1983). Hantaan virus particles contain three major structural proteins: the nucleocapsid or "N" protein and the "G1" and "G2" glycoproteins. Id. In addition, virions contain an RNA-dependent RNA polymerase function. Id. Like other members of the Bunyaviridae family, the viral genome is comprised of three RNA segments: small (S), middle (M) and large (L). Id.

More detailed examination of the molecular structure of Hantaan virus was provided following cloning and sequencing of cDNA's for the S and M segments. In their 1986 paper, Schmaljohn et al. reported that unlike other Bunyadviridae, the 1696 nucleotide Hantaan virus S segment did not code for a non-structural protein (NS). Schmaljohn et al., Virology 155: 633-643 (1986). Rather, they found a single open reading frame encoding a putative 428 amino acid polypeptide, presumed to be the N protein, a result consistent with earlier data from cell-free translation studies. Id. The cDNA for the N product is disclosed and claimed in U.S. Pat. No. 5,298,423.

In 1987, Schmaljohn et al. reported the 3616 base nucleotide sequence for the Hantaan virus M segment. Within this region, a single open reading frame encoding 1135 amino acids was found. Schmaljohn et al., Virology 157: 31-39 (1987). Amino-terminal sequence of the G1 and G2 glycoproteins demonstrated that this single open reading frame coded for both glycoproteins (5'-G1-G2-3'), probably expressed in the form of a polyprotein precursor that is cleaved post- or cotranslationally, both to separate the two glycoproteins and to remove the amino-terminal 17 amino acids of the G1 glycoprotein. Id. These data were confirmed later the same year by a different group. Yoo and Kang, Nuc. Acids Res. 15: 6299-6300 (1987). The cDNA's for the G1 and G2 products are disclosed and claimed in U.S. Pat. No. 5,298,423.

A second Hantavirus, the "Seoul" serotype, has been isolated and sequenced. Antic et al., Virus Res. 19: 47-58 (1991): Antic et al., Virus Res. 19: 59-66 (1991). The Hantaan and Seoul serotypes show about 75% sequence homology at the RNA level. Antic et al., Virus Res. 24: 35-46 (1992). Patients with HFRS caused by the Seoul serotype appear to suffer a milder clinical form of the disease. Recent studies indicate that six other Hantaviruses exist: Puumala, Prospect Hill, Thailand, Dobrava, Thottapalayam and Four Corners. Arikawa et al., Virology 176: 114-125 (1990); Xiao et al., Virology 198: 205-217 (1994); Chu et al., Virology 198: 196-204 (1994); Nichol et al., "Genetic Identification of a Novel Hantavirus Associated with an Outbreak of Acute Respiratory Illness in the Southwestern United States, " Science in press (1994). Only Hantaan, Seoul, Puumala , and Dobrava are known to cause HFRS. Four Corners was described recently and linked to an extremely deadly form of pulmonary distress in the southwest United States. Thottapalayam, Prospect Hill and Thailand are not known to cause human disease.

In 1988, the first use of a recombinant Hantavirus antigen as a diagnostic agent was reported. Schmaljohn et al., J. Gen. Virol. 69: 777-786 (1988). cDNA's corresponding to the S segment were used in a Baculovirus expression system, and the resulting N polypeptide showed specific reactivity with immune sera from rabbits, rats and humans or Hantaan virus-specific monoclonal antibodies. Id. These data were extended and confirmed in a second study, also involving a recombinant, Baculovirus-expressed N protein. Rossi et al., Arch. Virol. S1: 19-28 (1990). Together, these reports proved that recombinant Hantavirus proteins could serve effectively as diagnostic reagents in screening for Hantavirus infection.

Having confirmed that recombinantly-produced Hantavirus antigens were immunologically related to those produced by Hantavirus infection, researchers next sought to determine whether such antigens might be used as a vaccine to protect animals against infection by Hantavirus. In one such study, immunization with a vaccinia virus vectors expressing Hantaan virus glycoproteins not only elicited antibody responses to Hantaan virus antigens in mice, they also protected hamsters from Hantaan virus infection, as measured by indirect immunofluorescence of lung and kidney tissue. Schmaljohn et al., J. Virol. 64: 3162-3170 (1990). While promising, these data were deemed only to "demonstrate the feasibility of using expressed Hantaan virus proteins to immunize animals to Hantaan virus" and "should provide a basis for future exploitation of recombinant-expressed Hantaan virus proteins as potential human vaccines." Id. at page 3170.

A later report by Schamljohn et al. reported the development of a different vaccinia-based vaccine containing both the M and S segments of Hantaan virus. Schmaljohn et al., Vaccine 10: 10-13 (1992). In Dec. 1992, preliminary immunization data for the M+S vaccinia virus vaccine was presented at a meeting in India. There, it was shown that the M+S vaccine protected 3 out of 4 hamsters after a single immunization and 4 out of 4 hamsters given a secondary immunization. These data were admitted to be of no statistical relevance and "repeat preclinical experiments . . . with this potential human product" were reportedly in progress.

Even though mortality rates for HFRS have dropped over the past several decades, this syndrome still represents a significant threat to populations around the world, especially those in regions where high quality supportive care is not readily available. Therefore, it remains of utmost importance to develop a safe and effective vaccine against Hantavirus. Currently, no vaccines have been demonstrated to meet both of these criteria.

SUMMARY OF THE INVENTION

It is, therefore, an object of this invention to provide a vaccine, suitable for use in humans, that is capable of inducing a protective immune response specific for Hantavirus. In addition, it is an object of the invention to provide specific methodology for the safe and effective implementation of such a vaccine.

In satisfying the foregoing objective, there is provided a vaccine formulation suitable for use in a human, comprising:

(i) infectious vaccinia virus that comprises a polynucleotide encoding (a) the Hantavirus polypeptides designated N, G1 and G2 (SEQ ID NOS 3, 1 and 2 respectively), and (b) all vaccinia virus polypeptides necessary for replication of said virus in a cell derived from said human, but not a functional thymidine kinase; and (ii) a pharmaceutically-acceptable carrier, excipient or diluent, wherein said vaccine formulation comprises a single dose of 1.times.10.sup.5 to 7.times.10.sup.7 plaque-forming units of vaccinia virus.

In addition, there is provide a method for inducing a Hantavirus-protective immune response in a human, comprising the steps of:

(i) providing a vaccine formulation suitable for use in a human comprising (a) infectious vaccinia virus activity and comprising a polynucleotide encoding (1) the Hantavirus polypeptides designated N, G1 and G2 (SEQ ID NOS 3, 1 and 2 respectively), and (2) all vaccinia virus polypeptides necessary for replication of said virus in a cell derived from said human, but not a functional thymidine kinase; and (b) a pharmaceutically-acceptable carrier, excipient or diluent, (ii) administering said vaccine formulation to said human, wherein said vaccine formulation comprises a single dose of 1.times.10.sup.5 to 7.times.10.sup.7 plaque-forming units of vaccinia virus.

In a preferred embodiment, the expression of vaccine encoded polypeptides is under control of the vaccinia virus 11 kD promoter.

In another preferred emobidment, the Hantavirus polypeptides are derived from the Hantaan serotype. Preferred sequences in this regard are the G1 sequence (SEQ 10 NO: 1): ##STR1## the G2 sequence (SEQ ID NO: 2): ##STR2## and the N sequence (SEQ ID NO: 3): ##STR3## of which the first 17 amino acids of G1 are apparently cleaved to form the mature G1 protein and, therefore, are optional.

The preferred coding sequence for the G1, G2 and N polypeptides is (SEQ ID NO: 4): ##STR4##

and (SEQ ID NO: 5) ##STR5##

In a series of preferred embodiments, the vaccine single dose comprises 1.times.10.sup.5 to 1.times.10.sup.7 plaque-forming units, 1.times.10.sup.5 to 1.times.10.sup.6 plaque-forming units, 1.times.10.sup.5 to 5.times.10.sup.5 plaque-forming units or 3.4.times.10.sup.7 plaque-forming units.

In yet another preferred embodiment, the pharmaceutically-acceptable carrier, excipient or diluent further comprises lactose and human serum albumin, most preferably at 5% (w/v) and 1% (w/v) of said formulation, respectively.

In still another preferred embodiment, the vaccine formulation further comprises neomycin of no more than 25 .mu.g per single dose of said formulation.

In yet another preferred embodiment, the single dose is provided in a volume of 0.1 to 1.0 ml, with increments of 0.1 ml.

In still another preferred embodiment, the vaccine formulation is in a form suitable for a route of administration selected from the group consisting of subcutaneous, intramuscular and intradermal.

Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 Amino acid sequence (SEQ ID NO: 1) of Hantaan virus G1 glycoprotein. Bracketed region ([. . .]) indicate potentially cleaved residues.

FIG. 2 Amino acid sequence (SEQ ID NO: 2) of Hantaan virus G2 glycoprotein.

FIG. 3 Amino acid sequence (SEQ ID NO: 3) of Hantaan virus nucleocapsid N protein.

FIG. 4 Nucleotide sequence (SEQ ID NO: 4) of Hantaan virus M segment cDNA.

FIG. 5. Nucleotide sequence (SEQ 10 NO: 5) of Hantaan virus S segment c DNA.

DETAILED DESCRIPTION OF THE INVENTION

Vaccinia virus is a member of the Orthopox genus of the Poxvirus family with little virulence for humans. Although the exact origin of vaccinia virus is obscure, it is related to the cowpox virus used by Jenner and strains of vaccinia virus became the vaccines of choice for the prevention of smallpox. Baxby, "Vaccinia Virus, " in VACCINIA VIRUSES AS VECTORS FOR VACCINE ANTIGENS. G. V. Quinnan, ed., Elsevier, New York, N.Y., pp. 3-8 (1985). The smallpox vaccines used in the eradication effort were prepared on large scale by inoculating the shave abdomens of calves, sheep or water buffalo with seed stocks of vaccinia virus and harvesting the infected exudative lymph from the inoculation sites. Henderson and Arita, "Utilization of Vaccine in the Global Eradication of Smallpox," VACCINIA VIRUSES AS VECTORS FOR VACCINE ANTIGENS. G. V. Quinnan, ed., Elsevier, New York, N.Y., pp. 61-67 (1985). The novelty of the vaccination procedure used by Jenner caused alarm with some of his contemporaries. The ultimate eradication of smallpox following implementation of the Intensified Smallpox Eradication Program of the World Health Organization proved that skepticism to be without foundation.

Vaccinia virus has several biological properties which make it an excellent candidate for use as a live vaccine. First, it possesses a high degree of physical and genetic stability under even severe field conditions, reducing problems and expense in transport and storage. In addition, genomic stability makes the incorporation of one or more foreign genes for the antigens to be expressed more feasible than in other systems. Second, because vaccinia replicates in the cytoplasm of host cells and uses its own DNA and RNA polymerases, effects on the host cell's physiologic functions are minimized. Third, vaccinia virus has a wide host range, thus permitting use of a single vaccine in a large number of species. Fourth, both humoral and cellular immunity are mediated by vaccinia virus-based vaccines. And fifth, the duration of effectiveness of vaccinia immunization is relatively long. See Haber et al., Science 243: 51 (1989). Much of the early work geared towards a vaccinia virus vector was undertaken with vaccine development in mind. Weir et al., Proc. Nat'l Acad. Sci. USA 79: 1210-14 (1982); Mackett et al., Proc. Nat'l Acad. Sci. USA 79: 7415-19 (1982); Smith et al ., Nature 302: 490-95 (1983); Smith et al., Proc. Nat'l Acad. Sci. USA 80: 7155-59 (1983).

As with any vaccine, safety is a major concern with the use of vaccinia virus as a immunizing agent. The adverse reaction rate of 1 in 50,000, reported during smallpox vaccinations, was tolerated only because the disease it prevented was so devastating. Baxby (1985). Generalized vaccinia among persons without underlying illnesses is characterized by a vesicular rash of varying extent that is usually self-limited. In the event of the formation of skin lesions as a result of virus replication, there is a risk of bacterial superinfection. In addition, there is also a risk of the formation of a scar at the site of skin lesions if they occur. Several attenuated smallpox vaccine strains were developed but, due to lower potency, were not adopted for general use. Recent efforts towards genetic engineering of vaccinia virus have resulted in strains with decreased virulence. These efforts targeted the viral thymidine kinase, growth factor, hemagglutinin, 13.8 kD secreted protein and ribonucleotide reductase genes. Buller et al., Nature 317: 813 (1985); Buller et al., J. Virol. 62: 866 (1988); Flexner et al., Nature 330: 259 (1987); Shida et al., J. Virol. 62: 4474 (1988); Kotwal et al., Virology 117: 579 (1989); Child et al., Virology 174: 626 (1990). There also is interest in using other members of the poxvirus family, such as avipoxviruses, as limited host range vaccine vectors. Taylor et al., Virology 6: 497 (1988). For instance, U.S. Pat. No. 5,266,313, hereby incorporated by reference, discloses and claims a raccoon poxvirus-based vaccine for rabies virus. Thus, discussion of vaccinia in the following examples is not intended to suggest limitation of the possible vaccine vectors.

Recombinant vaccinia viruses have been used to express genes of nonviral pathogens such as bacteria, rickettsia and protozoa and, in some cases, have protected experimental animals from infection. Fields, Science 252: 1662-67 (1991). In addition, vaccinia-based rabies and rinderpest vaccines have been tested. Id. The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (env) gene has been cloned into a vaccinia vector and a phase trial was conducted with this virus. The vaccine appeared safe, and demonstrated the development of readily detectable, persistent in vivo T-cell proliferative and serum antibody responses to HIV-1 in vaccinia-naive persons. Cooney et al., Lancet 337: 567 (1991). A neutralizing antibody response was not seen but the expression of the env gene was low compared to levels now obtainable.

The pharmaceutical compositions of the present invention are advantageously administered in the form of injectable compositions. A typical composition for such purpose comprises a pharmaceutically acceptable carrier. For instance, the composition may contain human serum albumin in a phosphate buffer containing NaCl. Other pharmaceutically acceptable carriers include aqueous solutions, non-toxic excipients, including salts, preservatives, buffers and the like (REMINGTON'S PHARMACEUTICAL SCIENCES, 15th Ed., Easton ed., Mack Publishing Co., pp 1405-1412 and 1461-1487 (1975) and THE NATIONAL FORMULARY XIV, 14th Ed., American Pharmaceutical Association, Washington, DC (1975), both hereby incorporated by reference). Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oil and injectable organic esters such as ethyloleate. Aqueous carriers include water, alcoholic/aqueous solutions, saline solutions, parenteral vehicles such as sodium chloride, Ringer's dextrose, etc. Intravenous vehicles include fluid and nutrient replenishers. The pH and exact concentration of the various components the pharmaceutical composition are adjusted according to routine skills in the art. Goodman and Gilman, THE PHARMACOLOGICAL BASIS FOR THERAPEUTICS (7th ed.).

Typically, such vaccines are prepared as injectables, either as liquid solutions or suspensions; solid forms suitable for solution in, or suspension in, liquid prior to injection may also be prepared. The preparation also may be emulsified. The active immunogenic ingredient is often mixed with an excipient which is pharmaceutically-acceptable and compatible with the active ingredient. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol, or the like and combinations thereof. In addition, if desired, the vaccine may contain minor amounts of auxiliary substances such as wetting or emulsifying agents, pH-buffering agents, adjuvants or immunopotentiators which enhance the effectiveness of the vaccine.

The vaccines are conventionally administered parenterally, by injection, for example, either subcutaneously or intramuscularly. Additional formulations which are suitable for other modes of administration an include oral formulations. Oral formulations include such typical excipients as, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate and the like. The compositions take the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations or powders and contain 10%-95% of active ingredient, preferably 25-70%.

The term "unit dose" refers to physically discrete units suitable for use in humans, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required diluent, i.e., carrier or vehicle, and a particular treatment regimen. The quantity to be administered, both according to number of treatments and amount, depends on the subject to be treated, capacity of the subject's immune system to synthesize antibodies, and degree of protection desired. Precise amounts of active ingredient required to be administered depend on the judgment of the practitioner and are peculiar to each individual. However, suitable dosage ranges are on the order of one to several hundred micrograms of active ingredient per individual. Suitable regimes for initial administration and booster shots also vary but are typified by an initial administration followed in one or two week intervals by one or more subsequent injections or other administration.

The following examples are given by way of illustration and should not be construed as limiting the scope of the invention. The examples are drawn from a Investigational New Drug Application, submitted to the U.S. Food and Drug Administration on Jun. 25, 1993, entitled "Hantaan M--S (Vaccinia virus-vectored) Recombinant Vaccine (TSI-GSD 264), FDA IND NO. 5166, hereby incorporated by reference.

EXAMPLE 1

Construction of a Vaccinia-Based Hantavirus Vaccine

VACCINE CONSTRUCTION--Sequences pertinent to the construction and production of the candidate vaccine are illustrated in FIGS. 4 and 5 (SEQ ID NOS 4 and 5).

1. Expression of HFRS antigenic subunits in vaccinia virus: a. Construction of transfer vector plasmids.

BglII restriction sites were engineered near the 3'- and 5'-ends of complementary DNA (cDNA) representing the Hantaan virus M genome segment by site-directed mutagenesis. Digestion with BglII generated a restriction fragment of approximately 3.5 kB which contained the entire coding regions of the G1 and G2 envelope glycoproteins. For subcloning into the SmaI site of the vaccinia virus transfer vector pSC11, the DNA was treated with the large (Klenow) fragment of DNA polymerase I to produce blunt ends. The lac Z gene in the plasmid was deleted using the restriction enzymes PstI and XhoI.

Because animal experimentation with recombinants indicated that Hantaan virus nucleocapsid (N) protein, encoded by the S segment, conferred protection against challenge with Hantaan virus in concert with the glycoproteins, the S segment was included in construction of the recombinant vaccine candidate.

b. Preparation of vaccinia virus recombinants.

For vaccinia virus recombinations, confluent monolayers of Vero E6 cells in 25-cm.sup.2 flasks were infected at a multiplicity of infection of 0.03 plaque forming units (PFU) per cell with a seed vaccinia virus diluted in liquid Eagle's Minimal Essential Medium (MEM) containing Earles' salts. EMEM; Gibco, Gaithersburg, Md. This virus seed carried the designation "Conn 3E1, Vero 1, D3 in Saline A, 7, Mar. 87, 4.times.10.sup.6 PFU/ml." The Conn 3E1 seed was a 3X plaque-purified derivative of the licensed Connaught smallpox vaccine. (Conn-Master 17633). Before use in recombinant construction, it had been passaged once in Vero cells and harvested on day 3, titering at 4.times.10.sup.6 PFU/ml.

After incubation at 37.degree. C. for 4 h, the medium was removed and 2 ml of fresh EMEM was added. Prior to transfection of infected cells, 20 .mu.g of the plasmid transfer vector was diluted to 0.5 ml in a buffer containing 150 mM NaCl, 0.7 mM Na.sub.2 HPO.sub.4, 5 mM KCl, 20 mM HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) and 6 mM dextrose, adjusted to pH 7.05. Calcium chloride (25 .mu.l of 2.5M) was added slowly and the solution was incubated at room temperature for 0.5 to 1.0 h. The transfection mixture was added dropwise to the infected cell culture supernatants and cells were then incubated at 37.degree. C. for 3 h, after which the medium was removed. A virus-neutralizing antibody and fresh EMEM was added. The cells were incubated at 37.degree. C. until cytopathic effects were extensive and most of the cells had detached from the flask (4 to 5 days). Cells were then pelleted from the cell culture supernatant by centrifugation (8,000.times.g) and suspended in 10 mM Tris-HCl (pH 8.8). After two cycles of free-thawing (-70.degree. C./37.degree. C.), cells were sonicated on ice four times for 30 seconds each at a maximum output in a cup sonicator.

Because the lac Z gene had been removed from the plasmid transfer vector, recombinants could no longer be selected from wild-type vaccinia viruses by color. Consequently, an immunoplaque assay selection procedure was implemented. Confluent monolayers of Vero C1008 cells (Vero E6 cells, ATCC, CRL 1586) in 60 mm Petri dishes were infected with 10.sup.-1 to 10.sup.-3 dilutions of recombinant vaccinia viruses overlaid with EMEM, 5% fetal bovine serum and 50 .mu.g/ml gentamicin. Two days after infection, or when vaccinia virus plaques were clearly visible, medium was removed and monolayers rinsed once with physiological saline.

A 57 mm dry, nitrocellulose filter (Schleicher and Schuell, Keene, NH, BA85) was placed on the top of the monolayers and a piece of Whatman 3MM filter paper soaked in TBST buffer (10 mM Tris-HCl (pH 8.0), 150 mM NaCl, 0.05% Tween 20) was placed on top of the nitrocellulose. The filter and paper were left in place for about 5 min, after which the nitrocellulose was removed and placed in a blocking solution consisting of TBST and 10% calf serum. The filters were rocked at room temperature for 1 h.

The blocking solution was then replaced with polyclonal, hyperimmune, mouse ascitic fluid or monoclonal antibody ascitic fluid to Hantaan virus proteins diluted 1:500 in TBST and 10% calf serum. Normal mouse ascitic fluid was used for control assays. The filters were again rocked for 1 hour at room temperature, after which they were washed three times for 10 minutes each with TBST. Alkaline phosphatase-conjugated rabbit anti-mouse IgG (Promega Biotec, Madison, Wis.), diluted 1:4000 in TBST was incubated with the washed filters by rocking at room temperature for 10 min with TBST followed by incubation with a color developer solution consisting of 330 .mu.g NBT and 165 .mu.g BCIP/ml (Promega Biotec, Madison, Wis.) dissolved in 100 mM Tris-HCl (pH 9.7) and 100 mM MgCl. Color development was stopped after 5-10 minutes by rinsing the filters with sterile distilled water.

To recover recombinant viruses, dark purple spots on the filters were cut out with sharp scissors and placed into sterile 10 mM Tris-HCl (pH 8.8). The filter pieces in buffer were either frozen at -70.degree. C. until needed or were sonicated on ice at maximum output in a cup sonicator three times for 30 seconds and then assayed immediately. Three successive immunoselections were then performed. For all assays beyond the first selection, recombinant viruses were sonicated and then filtered through 0.45 .mu.m filters in order to ensure that plaques resulted from infection of a single vaccinia virus. Plaques obtained from recombinants expressing both the M and S segments were detectable with monoclonal antibodies to N, G1, G2, or with anti-Hantaan virus polyclonal ascitic fluid.

Following the three immunoplaque selections, two standard plaque assays under agarose were then performed by infecting confluent monolayers of Vero E6 cells in 60 mm dishes for 1 h and overlaying the infected cells with EMEM containing 5% fetal bovine serum, 50 .mu.g/ml gentamicin and 1% agarose (SeaKem, FMC Corp., Marine Colloids Div., Rockland, Me.). Random, visible plaques were picked with a sterile Pasteur pipette.

The recombinant viruses were then transferred to a vaccine production laboratory where additional plaque purification in certified cells was performed. Individual plaques previously recovered were diluted in EMEM, sonicated and plaque-purified three additional times from agarose-covered monolayers of a certified lot of MRC-5 human diploid lung cells (ATCC, CCL 171). Assays were performed in a decontaminated biological safety hood within the Vaccine Production Laboratory at United States Army Medical Research Institute of Infectious Disease (USAMRIID) in which no other infectious agents were being investigated. At each passage, plaque harvests were sonicated in sterile, physiologic saline and filtered through 0.45 .mu.m filters to reduce the possibility of vaccinia aggregation. An individual plaque picked from the third assay was used to infect certified MRC-5 cells and a small virus seed stock was prepared. This thrice plaque-purified virus stock, designated "HTN-REC VAX#3, 3pp MRC-5/VERO, HTN-M+HTN-S, MAR 90," was transferred to The Salk Institute--Government Services Division (TSI-GSD) in Swiftwater, Pa. There, it was expanded to produce a master seed in certified MRC-5 cells (see below).

c. Expression of Hantaan genes.

The lot #1 candidate double-recombinant vaccine (expressing Hantaan virus glycoprotein and nucleocapsid products) was examined by radiolabeling and electrophoresis of immunoprecipitated proteins. The proteins produced were indistinguishable from the authentic Hantaan virus proteins. Comparison of previous vaccinia recombinants expressing the M and S gene demonstrated that comparable levels of Hantaan envelope proteins G1 and G2 were produced with each recombinant. Amounts of radiolabeled N protein appeared considerably greater in the new recombinant vaccine. This might be due to improved expression of the S gene under control of the vaccinia virus 11 kD promoter, as opposed to the 7.5 kD promoter used in the previous recombinant. Wittek et al., J. Virol. 49: 371-378 (1984).

EXAMPLE 2

Manufacture of Seed Stocks and Vaccine Lots

Methods 1. Seed Stocks: a. Master Seed.

The thrice plaque-purified virus stock, designated "HTN-REC VAX#3, 3 pp MRC-5/VERO, HTN-M+HTN-S, MAR 90" (see above), was transferred to TSI-GSD for manufacture in certified MRC-5 cells. The production process is described briefly below. A 1:100 dilution of the seed material was used to inoculate 200 tissue culture flasks (150 cm.sup.2) of MRC-5 cells for production of master seed virus. Infected cells were harvested by centrifugation. After blending and sonicating the infected cells, virus was partially purified by centrifugation in sucrose. The resultant freeze-dried master seed, designated NTOO87, was stabilized with 1 gm percent human serum albumin (HSA).

b. Production Seed.

The Master Seed (NTOO87) was used for the manufacture of a production seed according to the following protocol. Two hundred tissue culture flask (150 cm.sup.2) cultures of MRC-5 cells were infected with a 1:100 dilution of the master seed virus. Infected cells were incubated to 4+ cytopathic effect (CPE). "4+ CPE" indicates total or near total loss of cell viability, characterized by loss of adherence to the growth vessel. Cells were harvested, blended and sonicated and the virus was then partially purified by sucrose centrifugation. HSA was added to 4% (v/v) as stabilizer and then this Production Seed, designated NTOO88, was freeze-dried under standard conditions. A Production Seed Control Fluid, designated NTO588, was prepared in parallel from uninfected cultures.

c. Lot 1.

Lot 1 of the recombinant vaccinia-vectored Hantaan vaccine was prepared by infecting 280 tissue culture flask (150 cm.sup.2) cultures of MRC-5 cells with a 1:100 dilution of Production Seed virus (NTOO88). The cultures were incubated for 3 days at which time cytopathic effect was maximum (4+). Infected cells were harvested and later frozen, thawed, blended, sonicated, clarified and resuspended. The resuspended material was frozen again. To begin purification of the bulk, the frozen material was thawed, sonicated, and pooled before concentration to 320 ml volume using a 300,000 MW low-protein binding membrane. This concentrated bulk was sonicated and then partially purified by centrifugation through sucrose. Fractions were titered and those with an acceptable titer (2.0.times.10.sup.8 PFU/ml) were pooled, giving a volume of 380 ml. This pool was dialyzed versus phosphate buffered saline (PBS) without calcium or magnesium (MR0039) to reduce the sucrose from 38% to 2.0% and then combined with an equal volume of stabilizer (10% lactose with 2 gm percent HSA). This material was then dispensed in 1 ml aliquots in sterile 6.5 ml vials and freeze-dried as "Lot 1-1-90" of the vaccine candidate, with the product number designation of TSI-GSD-264.

Control (uninfected) fluid was prepared at each step by shell-freezing the cells in EMEM and then blending, sonicating, centrifuging and supplementing with HSA. Routine safety testing of final bulk, final container and control fluids was satisfactory. These tests included bacterial sterility, including in vitro Mycobacterium culture, mycoplasma culture in broth and on agar, tissue culture testing for adventitious agents and general safety in mice after intracerebral inoculation.

EXAMPLE 3

Composition and Storage of Live Hantavirus (TSI-GSD 264, Lot #1-1-90 (Lot #1))

The product is a freeze-dried preparation of cell-cultured, Hantaan M+S recombinant vaccinia virus grown in certified MRC-5 cells at 35.degree. C. in Eagle's Minimum Essential Medium (EMEM) with 5% fetal bovine serum. After purification, the fetal bovine serum was reduced to an insignificant amount. The fetal bovine serum is removed during virus concentration with the Minitan tangential flow device (Millipore). The 300,000 MW cut-off retains virus particles and flushes out fetal bovine serum components. Any residual fetal bovine serum is incapable of penetrating the 30-60% sucrose gradient through which virus was run. Virus was retrieved from the 41-49% sucrose fractions. Final purified vaccine product was stabilized to a final concentration of 5% lactose and 1 gm percent human serum albumin (HSA), freeze-dried and sealed in an atmosphere of sterile, dry nitrogen. Each vial of dried product contains approximately 6.76.times.10.sup.7 PFU/ml. Due to variability in assaying for PFU, some variations may occur from test to test.

EXAMPLE 4

Safety Test of Hantavirus Vaccine for Adventitious Agents

Objective

To remove vaccinia virus from a preparation while other viruses remain.

Background

1. Type protocol for removal of vaccinia with 0.45 .mu.m filter (Nalgene model 245-0045) was provided by Dr. Smith of the Food and Drug Administration (FDA). This protocol had been abstracted from a submission accepted by the FDA for a vaccinia product manufactured by an anonymous company.

2. Results reported in subject protocol could not be duplicated. It is possible that the difference is in the effect of sonication. In the original study, sonication may have failed to dissociate virus from membranes so that it was removed by filtration. In contrast, we may have successfully dissociated the virus using what is presumed to be the same procedure and, as a consequence, could only partially remove the virus by filtration.

3. Preliminary experimentation with a number of vaccinia-specific antisera of human, rabbit and lymphocyte hybridoma origin demonstrated that vaccinia virus is not efficiently neutralized. We found that monoclonal antibody 7D11 was superior to all others tested, but could not neutralize more than 10.sup.5 virions. Thus, it was obvious that it would be necessary to remove any virus in excess of that amount (vaccine typically contains 10.sup.9 virions) before it could be tested successfully in the tissue culture safety test.

4. These factors necessitated additional modification of the protocol. Therefore, the filtration process was repeated a second time to reduce the pre-neutralization titer to 10.sub.5 virions.

Materials and Methods 1. Test Articles and Reagents:

a. Vaccinia-infected MRC-5 cells were frozen at -70.degree. C. until used. The material was thawed and the cell debris pelleted by centrifugation. The supernatant fluid was discarded and the pellet resuspended to its original volume. This material most closely approximated that used in vaccine manufacture. This suspension was sonicated twice for 20 seconds.

b. A BHV-1 herpes virus sample was prepared using standard methodology.

c. Filter--0.45 .mu.m Nalgene filter (Model #245-0045). 2. Virus Titration:

a. Vaccinia was titrated in triplicate using monolayers of Vero cells in 6-well plates. After adsorption of samples for 2 hours, cells were overlayed with media containing 0.6% agarose and incubated at 37.degree. C. in a CO.sub.2 -rich environment for 48 h. A second overlay, the same as above except for addition of neutral red, was added and the cells were incubated an additional 24 h. Plaque titers were determined by standard procedures.

b. Herpes virus was titrated in triplicate using monolayers of bovine turbinate cells in 6-well plates as described above except that a single overlay was used. After 72 hours incubation, the cells were fixed with 10% buffered formalin and the agar overlay was removed. The cells were then stained by flooding with crystal violet and plaque titers determined.

Procedures and Results

The vaccinia and herpesvirus pools were titrated before filtration. The pools were then filtered through a Nalgene 0.45 .mu.m filter (#245-0045), sampled, refiltered through a second filter and then resampled. Samples were titrated as summarized below.

TABLE 1______________________________________ Virus titer (log.sub.10 PFU/ml)Sample Vaccinia Herpes______________________________________Prefiltered virus pool 8.0 7.56Filtered one time 6.13 7.12Filtered two times 5.19 6.44______________________________________ Conclusion

Vaccinia virus could be reduced to approximately 10.sup.5 virions by sequential passage through two Nalgene 0.45 .mu.m filters. The residual virus could then be neutralized with monoclonal antibody.

EXAMPLE 5

Assessment of Hantavirus-Induced Dermatotropic Reaction

Objective

To compare the dermatropic properties of Hantaan (vaccinia-vectored) seed virus with an FDA reference virus.

Background

1. Traditionally, smallpox vaccine has been administered by multiple pressure inoculations. Successful primary vaccination or a "take" induces a localized skin lesion that resolves into a permanent scar. Production of this response is dependent upon dermatropic properties. These properties are estimated in the rabbit scarification test.

2. Presently, vaccine induced scars are highly undesirable. Therefore, TSI-GSD 264 vaccinia vectored Hantaan vaccine has been produced in cell culture so that it can be administered by subcutaneous or intramuscular inoculation. Consequently, retention of dermatropic properties are not essential. Nevertheless, the seed virus has been tested to ensure that the cell culture passage has not enhanced dermatropic reactogenicity.

3. Acceptability criteria is that the vaccine seed does not cause a more severe dermatropic reaction than the FDA reference vaccine.

Materials

1. Test article--Hantaan (vaccinia-vectored), production seed, Lot 1 (NT0088).

2. Control article--FDS reference vaccinia, Lot 2.

3. Test system--New Zealand White rabbits, 2 to 3 Kg, female.

Procedure

1. Rabbits were sedated with a Ketamine/Rompun mixture.

2. Hair was clipped from four, 2.times.5 cm areas on each side of the rabbit and scarified by vigorous rubbing with a "comb."

3. Serial dilutions of recombinant Hantaan vaccine seed and reference vaccinia virus were prepared in two sequences: (1) log.sub.10 dilutions 1:10 through 1: 10,000 and (2) log.sub.10 dilutions 1:30 through 1:30,000.

4. Rabbit 1 was inoculated by coating the scarified skin surface with 0.2 ml of dilution sequence 1 for the recombinant Hantaan vaccine on the four areas on the left side of rabbit 1. Corresponding dilutions of sequence 1 for the reference vaccine were placed on the right side of rabbit 1.

5. Rabbit 2 was treated similarly with dilution sequence 2.

6. Two additional rabbits were inoculated at two sites with the first two dilutions of the reference virus from either dilution sequence 1 or 2. Additionally, tissue reactions caused by the scarification were monitored in two rabbits by observing two scarification sites on each rabbit that were either left uninoculated or inoculated with diluent.

Results

Comparison of skin reactions were purely subjective. It was concluded, however, that the recombinant Hantaan vaccine produced a much less severe skin reaction than the FDA reference vaccine. The skin lesions produced by the Hantaan vaccine resolved and the scab was removed while the reference vaccine lesions retained a tightly attached scab.

Summary

The Hantaan (Vaccinia-Vectored) seed virus was less reactive than the FDA reference virus in the rabbit scarification test.

EXAMPLE 6

Testing of Hantavirus Vaccine for Pathogenicity in a Murine Model

Objective

To compare the mouse lethality of Hantaan M+S (vaccinia virus-vectored) vaccine with the FDA reference vaccinia vaccine Lot 2.

Materials

1. Vaccine

a. Hantaan M+S (vaccinia virus-vectored) vaccine, FB0264, Lot 1. b. FDA reference vaccinia, Lot 2.

2. Animals --<24 h old suckling mice, CD-1 strain, Charles River, Raliegh, N.C.

Procedure

1. Comparative titration of TSI and FDA vaccines were conducted in a single test using the final bulk of the Hantaan vaccine M+S (titer 2.1.times.10.sup.6 PFU/0.3 ml) and FDA reference vaccine (5.4.times.10.sup.7 PFU/0.3 ml), respectively.

2. Logarithmic dilutions of the vaccine were prepared. Two litters of 5 mice each were used for each dilution. Mice were inoculated intracerebrally with 0.03 ml of the appropriate dilutions and observed for 21 days.

3. Mouse lethality was calculated as the dose in PFU that killed 50% of mice (e.g., PFU/0.03 ml of vaccine divided by LD.sub.50 of vaccine).

Results TABLE 2______________________________________Test 1.Vaccine Dose/0.03 ml LD.sub.50 /0.03 ml PFU/LD.sub.50______________________________________TSI 2.1 .times. 10.sup.6 1.2 .times. 10.sup.4 175.0FDA 5.4 .times. 10.sup.7 1.3 .times. 10.sup.6 42.9______________________________________ TABLE 3______________________________________Test 2 (only data for FDA reference vaccinia shown)Vaccine Dose/0.03 ml LD.sub.50 /0.03 ml PFU/LD.sub.50______________________________________FDA 3.3 .times. 10.sup.6 1.5 .times. 10.sup.6 2.2______________________________________

2. Mathematical standardization of data: The data shown above demonstrates that when the FDA reference vaccine was diluted 1:16, virulence in mice was diluted approximately proportionately. Using that observation, the mouse virulence for the FDA vaccine is calculated to be 1.4 PFU/LD.sub.50 when given at the same titer as the M+S Hantaan virus vaccine (2.1.times.10.sup.6 PFU/0.3 ml).

Discussion

1. Mouse lethality of TSI Hantaan MS (vaccinia virus-vectored) vaccine was 175 PFU/LD.sub.50.

2. Mouse lethality of FDA vaccinia vaccine was calculated to be 1.4 PFU/LD.sub.50.

3. The mean time-to-death for the Hantaan was 10.76+/-4.7 days compared to 0.8+/-1.9 days for the FDA reference vaccinia.

Conclusion

The Hantaan M+S (vaccinia virus-vectored) vaccine is calculated to be 100-times less virulent than the FDA reference vaccine when administered by intracerebral inoculation to suckling mice less than 24 h old. The time-to-death also was increased markedly for the Hantaan vaccine which further indicates reduced virulence.

EXAMPLE 7

Preclinical Investigation and Characterization of Hantavirus Vaccine

The preclinical characterization of the vaccinia-vectored Hantaan vaccine, TSI-GSD-264, included comparisons with a collection of numerous vaccinia virus strains. The strains are listed in Table 4 below and the infectious virus titers noted are for virus seeds prepared by a single passage in MRC-5 cells and plaque assayed on VERO cells.

TABLE 4______________________________________Vaccinia Virus Strains Used for Virulence Comparisons TITER (plaque formingSTRAIN units/ml)______________________________________Wyeth Strain from ATCC 2.3 .times. 10.sup.8Lederle Strain from ATCC 9.5 .times. 10.sup.8Wyeth Licensed Vaccine (Dryvax) 2.4 .times. 10.sup.8Eistree Strain (Lister Vaccine) from ATCC 1.2 .times. 10.sup.8Connaught Licensed Vaccine 2.3 .times. 10.sup.8IHD Strain from ATCC 7.0 .times. 10.sup.8Bureau of Biologics Standard Strain 1.1 .times. 10.sup.8Western Reserve (mouse-adapted) Strain 6.5 .times. 10.sup.8TSI-GSD-241 2.0 .times. 10.sup.8TSI-GSD-264 1.2 .times. 10.sup.8______________________________________ TABLE 5______________________________________Virulence Comparison of Vaccinia Virus Strains (minimal dose in log.sup.10 giving lesions) ADULT MOUSE DOSE DOSESTRAINS VIRULENCE ERYTHEMA EROSION______________________________________Wyeth ATCC + 2 6Lederle + 2 5Wyeth Vaccine + 2 7Lister + 2 6Connaught + 3 6IHD ++++ 1 2BOB Standard + 2 5WR ++++ 1 1TSI-GSD-241 - 3 7TSI-GSD-264 - 4 7______________________________________ Relative rating with ++++ most virulent and avirulent.

The virus strains were examined for pock formation on chorioallantoic membranes of embryonated chicken eggs, formation of lesions after intradermal inoculation of adult rabbits, and intracerebral and intraperitoneal virulence for adult and suckling outbred mice. Representative data are presented in Table 5 above. For purposes of comparison, data are illustrated for both the vaccinia-vectored Hantaan vaccine candidate (TSI-GSD-264) and a cell-cultured smallpox vaccine (TSI-GSD-241, reference IND #4984) derived from the same virus seed ("Conn 3E1"), which in turn was a thrice plaque-picked derivation from the licensed Connaught vaccinia (Conn-Master 17633). Using these tests, both the vaccinia-vectored Hantaan vaccine candidate (TSI-GSD-264) and a cell cultured smallpox vaccine (TSI-GSD-241) were among the least virulent vaccinia strains tested and were comparable to the New York Board of Health, Bureau of Biologics reference strain.

A primary study compared the undiluted vaccinia-vectored Hantaan vaccine, TSI-GSD-264, to the licensed Wyeth vaccine, as well as to a cell-cultured smallpox vaccine (TSI-GSD-241, reference IND #4984). The TSI-GSD-264 booster was given to 4 monkeys in the study. An additional six monkeys received TSI-GSD 264 one year after immunization with vaccinia virus lacking any foreign gene insert either the cell-cultured parent virus or Wyeth Dryvax.TM.. Intradermal and subcutaneous administration of the vaccine candidate was well tolerated and all monkeys seroconverted. Cutaneous lesions were minimal and comparable among the three vaccines tested.

Of the four monkeys receiving primary immunization with TSI-GSD 264, neutralizing antibody to Hantaan virus was detected at 42 days post-inoculation in three monkeys. The fourth monkey developed neutralizing antibody after a boost. All monkeys had seroconverted, as measured by ELISA, after primary immunization. Of the monkeys initially immunized with a non-recombinant vaccinia and later immunized with TSI-GSD 264, none developed neutralizing antibody and two developed low ELISA titers to Hantaan.

One monkey from the study died 61/2 months after receiving the vaccine candidate as a primary immunization. It had not had any unusual response to immunization and its death was determined to be the result of gastric perforation. No pathologic lesions suggestive of vaccinia were noted. Another monkey which was inoculated with TSI-GSD 264 as its booster, was euthanized 8 months later because of chronic diarrhea and a generalized wasting condition attributed to Simian Retrovirus infection (SRV). Blood specimens obtained from the monkey four days prior to euthanasia were both seropositive and culture positive for SRV. In light of the fact that (i) most severe reactions to vaccinia virus inoculation occur within 30 days and (ii) these monkeys had no lesions suggestive of vaccinia virus infection, it is unlikely that these deaths were caused by inoculation with the candidate vaccine. The pathology reports are filed with the IND.

EXAMPLE 8

Human Clinical Studies with Hantavirus Vaccine

General Study Design

The preliminary phase of the study is an open label inoculation of four individuals with documented vaccinia immunization (Group 1), succeeded by inoculation of four vaccinia-naive individuals (Group 2) 21 days after the first group is inoculated. Previous vaccinia immunization are documented by medical records and unequivocal vaccinia scar. This is followed by a randomized trial in 24 vaccinia-naive volunteers (Group 3). Vaccinia immune globulin is available on site for the treatment of serious adverse reactions such as ocular, generalized or progressive vaccinia.

Group 1 (smallpox-immune) volunteers are admitted as inpatients in groups of two to four people and receive the vaccinia-vectored Hantaan vaccine candidate (open label) by the subcutaneous route. Groups 2, 3 and 4 (vaccine-naive) subjects are administered the vaccine candidate, in escalating doses, in like fashion. Inoculation is given in the deltoid region of the arm. The four vaccinia-immune individuals in Group 1 receive the vaccine in the arm in which there is no vaccinia scar from previous immunization. Previous vaccinia immunization is documented by medical records and unequivocal vaccinia scar.

Group 1, 2, 3 and 4 subjects are admitted 3 days prior to inoculation and remain as inpatients until 4 days after inoculation. Subjects are then discharged and assessed on an outpatient basis without periodic bleeding with clinical examinations for potential reactions or complications through day 21. Subjects developing a vesicular or open lesion suspected to contain vaccinia virus have the lesion covered with a dressing and are followed with subsequent daily clinical examinations and dressing changes by an investigator or the nursing staff until the lesion forms a scab.

Group 5 volunteers, all vaccinia-naive, are enrolled depending on availability as outpatient subjects. Group 5 volunteers are randomly assigned to one of two subgroups: one receives a single injection and the other receives a booster. The vaccinees are grouped as follows:

TABLE 6______________________________________ # of vaccinia boo-Group # volunteers immunity dose ster______________________________________1 4 immune 3.4 .times. 10.sup.5 PFU no(inpatient)2 4 non-immune 3.4 .times. 10.sup.5 PFU no(inpatient)3 4 non-immune 3.4 .times. 10.sup.6 PFU no(inpatient)4 4 non-immune 3.4 .times. 10.sup.7 PFU no(inpatient)5 24(outpatient) randomized:A non-immune 3.4 .times. 10.sup.7 PFU noB non-immune 3.4 .times. 10.sup.7 PFU yes______________________________________ On day 0, Groups 3A and 3B receive the vaccine candidate subcutaneously. After a 30 minute observation period for immediate untoward reactions, subjects are followed on an outpatient basis. Subjects have clear instructions on what to do if they experience an adverse reaction. On day 42, Group 3B receives a second injection of the vaccine. Outpatient follow-up, periodic bleeding and further clinical examinations as provided as needed. 1. Selection of Vaccine Dose:

a. The cell-cultured vaccinia virus candidate vaccine has a titer of 6.8.times.10.sup.7 PFU/ml. A dose of 0.5 ml of undiluted vaccine is administered subcutaneously, equaling an inoculum of 3.4.times.107 PFU. Preclinical studies in animals support the immunogenicity and safety of this undiluted vaccine dose. McClain et al., American Soc. Tropical Med. Hygiene Annual Meeting (1993).

2. Clinical Procedures: a. General Considerations.

All times mentioned below are referenced against the day of inoculation, which is customarily designated as Day 0. Physical activity one week prior to and during the first 4 weeks following inoculation is limited to each subject's usual level of activity. This minimizes abnormalities in serum enzyme levels associated with strenuous activity.

b. Inoculation and Immediate Observation.

Subjects remain under the direct supervision of the Principal Investigator or Associate Clinical Investigator for 30 minutes after inoculation. Injectable epinephrine and resuscitative equipment are available for the treatment of acute anaphylactic reaction. An aliquot of the remaining vaccine virus is retained for determination of virus titer and the remainder of the vaccine is destroyed by incineration in accordance with state regulations for disposal of medical waste.

c. Continued Inpatient Observation.

Members of Groups 1 and 2 are monitored for four days after inoculation on the inpatient ward. Temperature, pulse, respiratory rate, and blood pressure are monitored three times a day for three days prior to, and four days after, inoculation on the clinical ward. The interval between measurements is shortened in subjects with symptoms or fever (oral temperature >100.5.degree. F.). Inoculation sites are daily examined by measurement of erythema and induration, measuring 2 perpendicular directions across the lesion. Photographs are taken as needed. Any vesicular eruption or crusting is noted and cultured for virus. During the inpatient phase, responses to inquiries about local or systemic complaints (pruritus, pain, malaise, fatigue, etc.) are recorded daily. Attempts are made to quantify the duration and severity of complaints. A scale of 0 to 3 is used to measure the degree to which symptoms interfere with activities of daily living. Evaluations are detailed on clinical evaluation forms.

d. Outpatient Observations.

Volunteers are followed with vital signs and physical examinations for up to 11 days following inoculation during the outpatient phase of the protocol. Each participant is advised that staff are available on a 24-hour basis for the duration of the study in order to screen any subject who is suffering any side effect of the inoculation. These side effects include fever, itching, rash or any other symptoms, regardless of their opinion as to the relevance of the symptom to the inoculation. The nursing staff evaluates the complaint and notes the complaint in the clinical protocol record. The nursing staff then reports all such complaints to the Principal Investigator or Associate Clinical Investigator for evaluation and instructions about required follow-up care. Any subject developing a vesicular lesion at the site of inoculation has the lesion covered with a dressing until such a lesion has formed a scab. In addition, subjects return for scheduled bleeding as per the appropriate bleed schedule. At 63 days after inoculation a clinical summary of protocol participation is entered into the clinical record for each volunteer. A copy of this summary is sent to the volunteer's official medical record unless a volunteer specifically indicates that he/she does not want this done.

3. Laboratory Studies:

a. Baseline screening laboratory studies are as described above. Protocol participation studies include periodic examinations of the following: CBC with differential and platelets, urinalysis, serum chemistries, serum viremia, serum vaccinia antibody, serum Hantaan antibody and lymphocyte immune responses to Hantaan antigen. Remaining serum samples are maintained frozen at -40.degree. C. in the USAMRIID serum bank and available for additional studies and/or repeat of selected studies as needed, unless volunteers specifically exclude use of samples for additional studies. Fluid in vesicular or weeping lesions at the site of inoculation or at distant sites is be sampled and placed in viral isolation transport medium to attempt virus recovery. Serum antibody determinations include ELISA reactivity with whole virus Hantaan antigen and vaccinia antigen and plaque reduction neutralization of Hantaan virus.

EXAMPLE 9

Results of Clinical Trials With M+S Hantavirus (Vaccinia-Vectored) Vaccine

Clinical trials of the vaccinia-vectored M+S Hantavirus vaccine are expected to show the vaccine to be safe and effective in humans. Vaccine recipients are expected to produce significant humoral response as measured by enzyme-linked immunosorbent assays (ELISA). This response should be characterized by the production of both neutralizing and non-neutralizing antibodies, the latter being measured by plaque reduction neutralization assays. In addition, lymphocyte blastogenesis assays are expected to demonstrate that lymphoytes from vaccine recipients proliferate and produce cytokines upon exposure to Hantavirus antigen in vitro.

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NO:2:SerGluThrProLeuThrProValTrpAsnAspAsnAlaHisGlyVal151015GlySerValProMetHisThrAspLeuGluLeuAspPheSerLeuThr202530SerSerSerLysTyrThrTyrArgArgLysLeuThrAsnProLeuGlu354045GluAlaGlnSerIleAspLeuHisIleGluIleGluGluGlnThrIle505560GlyValAspValHisAlaLeuGlyHisTrpPheAspGlyArgLeuAsn65707580LeuLysThrSerPheHisCysTyrGlyAlaCysThrLysTyrGluTyr859095ProTrpHisThrAlaLysCysHisTyrGluArgAspTyrGlnTyrGlu100105110ThrSerTrpGlyCysAsnProSerAspCysProGlyValGlyThrGly115120125CysThrAlaCysGlyLeuTyrLeuAspGlnLeuLysProValGlySer130135140AlaTyrLysIleIleThrIleArgTyrSerArgArgValCysValGln145150155160PheGlyGluGluAsnLeuCysLysIleIleAspMetAsnAspCysPhe165170175ValSerArgHisValLysValCysIleIleGlyThrValSerLysPhe180185190SerGlnGlyAspThrLeuLeuPhePheGlyProLeuGluGlyGlyGly195200205LeuIlePheLysHisTrpCysThrSerThrCysGlnPheGlyAspPro210215220GlyAspIleMetSerProArgAspLysGlyPheLeuCysProGluPhe225230235240ProGlySerPheArgLysLysCysAsnPheAlaThrThrProIleCys245250255GluTyrAspGlyAsnMetValSerGlyTyrLysLysValMetAlaThr260265270IleAspSerPheGlnSerPheAsnThrSerThrMetHisPheThrAsp275280285GluArgIleGluTrpLysAspProAspGlyMetLeuArgAspHisIle290295300AsnIleLeuValThrLysAspIleAspPheAspAsnLeuGlyGluAsn305310315320ProCysLysIleGlyLeuGlnThrSerSerIleGluGlyAlaTrpGly325330335SerGlyValGlyPheThrLeuThrCysLeuValSerLeuThrGluCys340345350ProThrPheLeuThrSerIleLysAlaCysAspLysAlaIleCysTyr355360365GlyAlaGluSerValThrLeuThrArgGlyGlnAsnThrValLysVal370375380SerGlyLysGlyGlyHisSerGlySerThrPheArgCysCysHisGly385390395400GluAspCysSerGlnIleGlyLeuHisAlaAlaAlaProHisLeuAsp405410415LysValAsnGlyIleSerGluIleGluAsnSerLysValTyrAspAsp420425430GlyAlaProGlnCysGlyIleLysCysTrpPheValLysSerGlyGlu435440445TrpIleSerGlyIlePheSerGlyAsnTrpIleValLeuIleValLeu450455460CysValPheLeuLeuPheSerLeuValLeuLeuSerIleLeuCysPro465470475480ValArgLysHisLysLysSer485(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 429 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:MetAlaThrMetGluGluLeuGlnArgGluIleAsnAlaHisGluGly151015GlnLeuValIleAlaArgGlnLysValArgAspAlaGluLysGlnTyr202530GluLysAspProAspGluLeuAsnLysArgThrLeuThrAspArgGlu354045GlyValAlaValSerIleGlnAlaLysIleAspGluLeuLysArgGln505560LeuAlaAspArgIleAlaThrGlyLysAsnLeuGlyLysGluGlnAsp65707580ProThrGlyValGluProGlyAspHisLeuLysGluArgSerMetLeu859095SerTyrGlyAsnValLeuAspLeuAsnHisLeuAspIleAspGluPro100105110ThrGlyGlnThrAlaAspTrpLeuSerIleIleValTyrLeuThrSer115120125PheValValProIleLeuLeuLysAlaLeuTyrMetLeuThrThrArg130135140GlyArgGlnThrThrLysAspAsnLysGlyThrArgIleArgPheLys145150155160AspAspSerSerPheGluAspValAsnGlyIleArgLysProLysHis165170175LeuTyrValSerLeuProAsnAlaGlnSerSerMetLysAlaGluGlu180185190IleThrProGlyArgTyrArgThrAlaValCysGlyLeuTyrProAla195200205GlnIleLysAlaArgGlnMetIleSerProValMetSerValIleGly210215220PheLeuAlaLeuAlaLysAspTrpSerAspArgIleGluGlnTrpLeu225230235240IleGluProCysLysLeuLeuProAspThrAlaAlaValSerLeuLeu245250255GlyGlyProAlaThrAsnArgAspTyrLeuArgGlnArgGlnValAla260265270LeuGlyAsnMetGluThrLysGluSerLysAlaIleArgGlnHisAla275280285GluAlaAlaGlyCysSerMetIleGluAspIleGluSerProSerSer290295300IleTrpValPheAlaGlyAlaProAspArgCysProProThrCysLeu305310315320PheIleAlaGlyIleAlaGluLeuGlyAlaPhePheSerIleLeuGln325330335AspMetArgAsnThrIleMetAlaSerLysThrValGlyThrSerGlu340345350GluLysLeuArgLysLysSerSerPheTyrGlnSerTyrLeuArgArg355360365ThrGlnSerMetGlyIleGlnLeuGlyGlnArgIleIleValLeuPhe370375380MetValAlaTrpGlyLysGluAlaValAspAsnPheHisLeuGlyAsp385390395400AspMetAspProGluLeuArgThrLeuAlaGlnSerLeuIleAspVal405410415LysValLysGluIleSerAsnGlnGluProLeuLysLeu420425(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 3401 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:ATGGGGATATGGAAGTGGCTAGTGATGGCCAGTTTAGTATGGCCTGTTTTGACACTGAGA60AATGTCTATGACATGAAAATTGAGTGCCCCCATACAGTAAGTTTTGGGGAAAACAGTGTG120ATAGGTTATGTAGAATTACCCCCCGTGCCATTGGCCGACACAGCACAGATGGTGCCTGAG180AGTTCTTGTAACATGGATAATCACCAATCGTTGAATACAATAACAAAATATACCCAAGTA240AGTTGGAGAGGAAAGGCTGATCAGTCACAGTCTAGTCAAAATTCATTTGAGAGAGTGTCC300ACTGAAGTTGACTTGAAAGGAACATGTGTTCTAAAACACAAAATGGTGGAAGAATCATAC360CGTAGTAGGAAATCAGTAACCTGTTACGACCTGTCTTGCAATAGCACTTACTGCAAGCCA420ACACTATACATGATTGTACCAATTCATGCATGCAATATGATGAAAAGCTGTTTGATTGCA480TTGGGACCATACAGGTACAGGTGGTTTATGAGAGAAGTTACTGTATGACAGGAGTCCTGA540TTGAAGGGAAATGCTTTGTCCCAGATCAAAGTGTGGTCAGTATTATCAAGCATGGGATCT600TTGATATTGCAAGTTTTCATATTGTATGTTTCTTTGTTGCAGTTAAAGGGAATACTTATA660AAATTTTTGAACAGGTTAAGAAATCCTTTGAATCAACATGCAATGATACAGAGAATAAAG720TGCAAGGATATTATATTTGTATTGTAGGGGGAAACTCTGCACCAATATATGTTCCAACAC780TTGATGATTTCAGATCCATGGAAGCATTTACAGGAATCTTCAGATCACCACATGGGGAAG840ATCATGATCTGGCTGGAGAAGAAATTGCATCTTATTCTATAGTCGGACCTGCCAATGCAA900AAGTTCCTCATAGTGCTAGCTCAGATACATTGAGCTTGATTGCCTATTCAGGTATACCAT960CTTATTCTTCCCTTAGCATCCTAACAAGTTCAACAGAAGCTAAGCATGTATTCAGCCCTG1020GGTTGTTCCCAAAACTTAATCACACAAATTGTGATAAAAGTGCCATACCACTCATATGGA1080CTGGGATGATTGATTTACCTGGATACTACGAAGCTGTCCACCCTTGTACAGTTTTTTGCG1140TATTATCAGGTCCTGGGGCATCATGTGAAGCCTTTTCTGAAGGCGGGATTTTCAACATAA1200CCTCTCCCATGTGCTTAGTGTCAAAACAAAATCGATTCCGGTTAACAGAACAGCAAGTGA1260ATTTTGTGTGTCAGCGAGTGGACATGGACATTGTTGTGTACTGCAACGGGCAGAGGAAAG1320TAATATTAACAAAAACTCTAGTTATTGGACAGTGTATATATACTATAACAAGCTTATCAT1380TACTACCTGGAGTAGCACATTCTATTGCTGTTGAATTGTGTGTACCTGGGTTCCATGGTT1440GGGCCACAGCTGCTCTGCTTGTTACATTCTGTTTCGGATGGGTTCTTATACCAGCAATTA1500CATTTATCATACTAACAGTCCTAAAGTTCATTGCTAATAATTTTCACACAAGTAATCAAG1560AGAATAGGCTAAAATCAGTACTTAGAAAGATAAAGGAAGAGTTTGAAAAAACAAAAGGCT1620CAATGGTATGTGATGTCTGCAAGTATGAGTGTGAAACATATAAAGAATTAAAGGCACACG1680GGGTATCATGCCCCCAATCTCAATGTCCTTACTGTTTTACTCATTGTGAACCTACAGAAG1740CAGCATTCCCAGTCCATTACAAGGTATGCCAAGTTACTCACAGATTCAGGGATGATCTAA1800AGAAAACTGTTACTCCTCAAAATTTTACACCAGGATGTTACCGGACACTAAATTTATTTA1860GATACAAAAGCAGGTGCTACATCTTTACAATGTGGATATTTCTTCTTGTCTTAGAATCCA1920TACTGTGGGCTGCAAGTGCATCAGAGACACCATTAACTCCTGTCTGGAATGACAATGCCC1980ATGGGGTAGGTTCTGTTCCTATGCATACAGATTTAGAGCTTGATTTCTCTTTAACATCCA2040GTTCCAAGTATACATACCGTAGGAAGTTAACAAACCCACTTGAGGAAGCACAATCCATTG2100ACCTACATATTGAAATAGAAGAACAGACAATTGGTGTTGATGTGCATGCTCTAGGACACT2160GGTTTGATGGTCGTCTTAACCTTAAAACATCCTTTCACTGTTATGGTGCTTGTACAAAGT2220ATGAATACCCTTGGCATACTGCAAAGTGCCATTATGAAAGAGATTACCAATATGAAACGA2280GCTGGGGTTGTAATCCATCAGATTGTCCTGGGGTGGGCACAGGCTGTACAGCATGTGGTT2340TATACCTAGATCAACTGAAACCAGTTGGTAGTGCTTATAAAATTATCACAATAAGGTACA2400GCAGGAGAGTCTGTGTTCAGTTTGGGGAGGAAAACCTTTGTAAGATAATAGAGATGAATG2460ATTGTTTTGTATCTAGGCATGTTAAGGTCTGCATAATTGGTACAGTATCTAAATTCTCTC2520AGGGTGATACCTTATTGTTTTTTGGACCGCTTGAAGGTGGTGGTCTAATATTTAAACACT2580GGTGTACATCCACATGTCAATTTGGTGACCCAGGAGATATCATGAGTCCAAGAGACAAAG2640GTTTTTTATGCCCTGAGTTTCCAGGTAGTTTCAGGAAGAAATGCAACTTTGCTACTACCC2700CTATTTGTGAGTATGATGGAAATATGGTCTCAGGTTACAAGAAAGTGATGGCGACAATTG2760ATTCCTTCCAATCTTTTAATACAAGCACTATGCACTTCACTGATGAAAGGATAGAGTGGA2820AAGACCCTGATGGAATGCTAAGGGACCATATAAACATTTTAGTAACGAAGGACATTGACT2880TTGATAACCTTGGTGAAAATCCTTGCAAAATTGGCCTACAAACATCTTCTATTGAGGGGG2940CCTGGGGTTCTGGTGTGGGGTTCACATTAACATGTCTGGTATCACTAACAGAATGTCCTA3000CCTTTTTGACCTCAATAAAGGCTTGTGATAAGGCTATCTGTTATGGTGCAGAGAGTGTAA3060CATTGACAAGAGGACAAAATACAGTCAAGGTATCAGGGAAAGGTGGCCATAGTGGTTCAA3120CATTTAGGTGTTGCCATGGGGAGGACTGTTCACAAATTGGACTCCATGCTGCTGCACCTC3180ACCTTGACAAGGTAAATGGGATTTCTGAGATAGAAAATAGTAAAGTATATGATGATGGGG3240CACCGCAATGTGGGATAAAATGTTGGTTTGTTAAATCAGGGGAATGGATTTCAGGGATAT3300TCAGTGGTAATTGGATTGTACTCATTGTCCTCTGTGTATTTCTATTGTTCTCCTTGGTTT3360TACTAAGCATTCTCTGTCCCGTAAGGAAGCATAAAAAATCA3401(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1286 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:ATGGCAACTATGGAGGAATTACAGAGGGAAATCAATGCCCATGAGGGTCAATTAGTGATA60GCCAGGCAGAAGGTGAGGGATGCAGAAAAACAGTATGAAAAGGATCCAGATGAGTTGAAC120AAGAGAACATTAACTGACCGAGAGGGCGTTGCAGTATCTATCCAGGCAAAAATTGATGAG180TTAAAAAGGCAACTGGCAGATAGGATTGCAACTGGGAAAAACCTTGGGAAGGAACAAGAT240CCAACAGGGGTGGAGCCTGGAGACCATCTGAAAGAGAGGTCAATGCTCAGTTATGGTAAT300GTGCTGGATTTAAACCATTTGGATATTGATGAACCTACAGGACAGACAGCAGACTGGCTG360AGCATCATCGTCTATCTTACATCCTTTGTCGTCCCGATACTTCTGAAAGTCCTGTATATG420TTGACAACAAGGGGGAGGCAAACTACCAAGGATAATAAAGGGACCCGGATTCGATTTAAG480GATGATAGCTCGTTCGAGGATGTTAACGGTATCCGGAAACCAAAACATCTTTACGTGTCC540TTGCCAAATGCACAGTCAAGCATGAAGGCAGAAGAGATTACACCTGGTAGATATAGAACA600GCAGTCTGTGGGCTCTACCCTGCACAGATTAAGGCACGGCAGATGATCAGTCCAGTTATG660AGTGTAATTGGTTTTCTAGCATTAGCAAAGGACTGGAGTGATCGTATCGAACAATGGTTA720ATTGAACCTTGCAAGCTTCTTCCAGATACAGCAGCAGTTAGCCTCCTCGGTGGTCCTGCA780ACAAACAGGGACTACTTACGGCAGCGGCAAGTGGCATTAGGCAATATGGAGACAAAGGAG840TCAAAGGCTATACGCCAGCATGCAGAAGCAGCTGGCTGTAGCATGATTGAAGATATTGAG900TCACCATCATCAATATGGGTTTTTGCTGGAGCACCAGACCGTTGTCCACCAACATGTTTG960TTTATAGCAGGTATTGCTGAGCTTGGGGCATTTTTTTCCATCCTGCAGGACATGCGAAAT1020ACAATCATGGCATCTAAGACGTTGGAACATCTGAGGAGAAGCTACGGAAGAAATCATCAT1080TTTATCAGTCCTACCTCAGAAGGACACAATCAATGGGGATACAACTAGGCCAGAGAATTA1140TTGTGCTCTTCATGGTTGCCTGGGGAAAGGAGGCTGTGGACAACTTCCACTTAGGGGATG1200ATATGGATCCTGAGCTAAGGACACTGGCACAGAGCTTGATTGATGTCAAAGTGAAGGAAA1260TCTCCAACCAAGAGCCTTTGAAACTC1286__________________________________________________________________________

Claims

1. A vaccine formulation suitable for use in a human, comprising:

(i) infectious vaccinia virus that comprises a DNA molecule encoding

(a) the Hantaan virus polypeptides designated N, G1 and G2, and

(b) all vaccinia virus polypeptides necessary for replication of said virus in a cell derived from said human, but not a functional thymidine kinase; and

(ii) a pharmaceutically-acceptable carrier, excipient or diluent,

wherein said vaccine formulation comprises a single dose of 5.times.10.sup.5 to 7.times.10.sup.7 plaque forming units of vaccinia virus.

2. The vaccine formulation according to claim 1, wherein the nucleotide sequence encoding said G1 polypeptide and said G2 polypeptide is operably linked to the vaccinia virus 7.5 kD promoter, and wherein the nucleotide sequence encoding said N polypeptide is operably linked to the vaccinia virus 11 kD promoter.

3. The vaccine formulation according to claim 1, wherein said G1 has the sequence (SEQ ID NO: 1): ##STR6## said G2 has the sequence (SEQ ID NO: 2): ##STR7## and said N has the sequence (SEQ ID NO: 3): ##STR8##

4. The vaccine formulation according to claim 3, wherein said DNA molecule comprises a wild-type vaccinia virus genome with the cDNA of the M and S genomic segments of the Hantaan serotype inserted in the vaccinia virus thymidine kinase coding region.

5. The vaccine formulation according to claim 4, wherein said cDNA comprises the sequence (SEQ ID NO: 4): ##STR9## and (SEQ ID NO: 5): ##STR10##

6. The vaccine formulation according to claim 1, wherein said single dose comprises 5.times.10.sup.5 to 7.times.10.sup.7 plaque-forming units.

7. The vaccine formulation according to claim 1, wherein said single dose comprises 5.times.10.sup.5 to 1.times.10.sup.6 plaque-forming units.

8. The vaccine formulation according to claim 1, wherein said single dose comprises 5.times.10.sup.5 to plaque-forming units.

9. The vaccine formulation according to claim 1, wherein said single dose comprises 3.4.times.10.sup.7 plaque-forming units.

10. The vaccine formulation according to claim 9, wherein said pharmaceutically-acceptable carrier, excipient or diluent further comprises lactose and human serum albumin.

11. The vaccine formulation according to claim 10, wherein said lactose is 5% (w/v) of said formulation and said human serum albumin is 1% (w/v) of said formulation.

12. The vaccine formulation according to claim 11, wherein said formulation further comprises neomycin of no more than 25 .mu.g per single dose of said formulation.

13. The vaccine formulation according to claim 12, wherein said single dose of said formulation is in a volume of 0.1 to 1.0 ml.

14. The vaccine formulation according to claim 1, wherein said formulation is in a form suitable for a route of administration selected from the group consisting of subcutaneous, intramuscular and intradermal.

15. A method for inducing a Hantavirus-protective immune response in a human, comprising the steps of:

(i) providing a vaccine formulation suitable for use in a human comprising

(a) infectious vaccinia virus activity and comprising a DNA molecule encoding

(1) the Hantaan virus polypeptides designated N, G1 and G2, and

(2) all vaccinia virus polypeptides necessary for replication of said virus in a cell derived from said human, but not a functional thymidine kinase; and

(b) a pharmaceutically-acceptable carrier, excipient or diluent, and

(ii) administering said vaccine formulation to said human,

wherein a single dose of said vaccine formulation comprises 5.times.10.sup.5 to 7.times.10.sup.7 plaque forming units of vaccinia virus.

16. The method according to claim 15, wherein the nucleotide sequence encoding said G1 polypeptide and said G2 polypeptide is operably linked to the vaccinia virus 7.5 kD promoter, and wherein the nucleotide sequence encoding said N polypeptide is operably linked to the vaccinia virus 11 kD promoter.

17. The method according to claim 16, wherein said G1 has the sequence (SEQ ID NO: 1): ##STR11## said G2 has the sequence (SEQ ID NO: 2): ##STR12## and said N has the sequence (SEQ ID NO: 3): ##STR13##

18. The method according to claim 17, wherein said DNA molecule comprises a wild-type vaccinia virus genome with the cDNA of the M and S genomic segments of the Hantaan serotype inserted in the vaccinia virus thymidine kinase coding region.

19. The method according to claim 18, wherein said cDNA comprises the sequence: (SEQ ID NO: 4): ##STR14## and (SEQ ID NO: 5): ##STR15##

20. The method according to claim 15, wherein said single dose comprises 5.times.10.sup.5 to 7.times.10.sup.7 plaque-forming units.

21. The method according to claim 15, wherein said single dose comprises 5.times.10.sup.5 to 1.times.10.sup.6 plaque-forming units.

22. The method according to claim 15, wherein said single dose comprises 5.times.10.sup.5 plaque-forming units.

23. The method according to claim 15, wherein said single dose comprises 3.4.times.10.sup.7 plaque-forming units.

24. The method according to claim 23, wherein said pharmaceutically-acceptable carrier, excipient or diluent further comprises lactose and human serum albumin.

25. The method according to claim 24, wherein said lactose is 5% (w/v) of said formulation and said human serum albumin is 1% (w/v) of said formulation.

26. The method according to claim 25, wherein said formulation further comprises neomycin of no more than 25 .mu.g per single dose of said formulation.

27. The method according to claim 26, wherein said single dose of said formulation is in a volume of 0.1 to 1.0 ml.

28. The method according to claim 27, wherein said administering is by a route selected from the group consisting of subcutaneous, intramuscular and intradermal.