Immunogenicity and Efficacy of TNX-1800, A Live Virus Recombinant Poxvirus Vaccine Candidate, Against SARS-CoV-2 Challenge in Nonhuman Primates

Awasthi, M.; Macaluso, A.; Myscofski, D.; Prigge, J.; Koide, F.; Noyce, R. S.; Fogarty, S.; Stillwell, H.; Goebel, S. J.; Daugherty, B.; Nasar, F.; Bavari, S.; Lederman, S.

doi:10.1101/2023.09.19.558485

bioRxiv · 10.1101/2023.09.19.558485

Immunogenicity and Efficacy of TNX-1800, A Live Virus Recombinant Poxvirus Vaccine Candidate, Against SARS-CoV-2 Challenge in Nonhuman Primates

Awasthi, M.·Macaluso, A.·Myscofski, D.·Prigge, J.·Koide, F.·Noyce, R. S.·Fogarty, S.·Stillwell, H.·Goebel, S. J.·Daugherty, B.·Nasar, F.·Bavari, S.·Lederman, S.

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Abstract

TNX-1800 is a synthetically derived live chimeric Horsepox Virus (rcHPXV) vaccine expressing Wuhan SARS-CoV-2 spike (S) protein. The primary objective of this study was to evaluate the immunogenicity and efficacy of TNX-1800 in two nonhuman primate species challenged with USA-WA1/2020 SARS-CoV-2. TNX-1800 vaccination was well tolerated, as indicated by the lack of serious adverse events or significant changes in clinical parameters. A single dose of TNX-1800 generated robust humoral responses in African Green Monkeys and Cynomolgus Macaques, as measured by the total binding anti-SARS-CoV-2 S IgG and neutralizing antibody titers against the USA-WA1/2020 strain. In Cynomolgus Macaques, a single dose of TNX-1800 induced a strong interferon-gamma (IFN-{gamma}) mediated T cell response, promoting both pathogen clearance in the upper and lower airways and generation of systemic neutralizing antibody response against WA strain SARS-CoV-2. Future studies will assess the efficacy of TNX-1800 against newly emerging variants and demonstrate its safety in humans.

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Awasthi, M., Macaluso, A., Myscofski, D., Prigge, J., Koide, F., Noyce, R. S., Fogarty, S., Stillwell, H., Goebel, S. J., Daugherty, B., Nasar, F., Bavari, S., Lederman, S.. 2023-09-20. Immunogenicity and Efficacy of TNX-1800, A Live Virus Recombinant Poxvirus Vaccine Candidate, Against SARS-CoV-2 Challenge in Nonhuman Primates. https://doi.org/10.1101/2023.09.19.558485

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