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.
Subject(s)
Severe Acute Respiratory SyndromeABSTRACT
TNX-1800 is a preclinical stage synthetic derived live chimeric horsepox virus vaccine that comprises an engineered SARS-CoV-2 spike (S) gene expression cassette. The objectives of this study were to assess the immunogenicity and tolerability of TNX-1800 administration in Syrian golden hamsters and New Zealand white rabbits. Animals were vaccinated via percutaneous inoculation and evaluated for dose tolerance and immunogenicity at three different dose levels. The 28-day study data showed that the single percutaneous administration of three TNX-1800 vaccine dose levels was well tolerated in both hamsters and rabbits. For all dose levels, rabbits had more dermal observations than hamsters at the same dose levels. Vaccine-induced viral load four weeks post-dosing was below the detection level for both species.