Animal Pre-Clinical Study of an Inactivated SARS-CoV-2 Vaccine candidate (Osvid-19 ): Immunogenicity, Protective, and Safety Aspects

ABSTRACT

Background: This study aimed to evaluate the outcomes of preclinical studies on the safety and immunogenicity of an inactivated COVID-19 vaccine candidate to warrant further clinical evaluation. Method(s) SARS-CoV-2 positive nasopharyngeal swab specimens were confirmed by real-time polymerase chain reaction and next-generation sequencing. The safety and immunogenicity tests of the COVID-19 vaccine were carried out in rats and Rhesus monkeys, and Balb/C mice and Rhesus monkeys, respectively. Result(s) The candidate vaccine was well tolerated and induced promising levels of SARS-CoV-2- specific IgG1, IgG2a, and Granzyme B in Balb/C mice, and anti-SARS-CoV-2 spike IgG and neutralizing antibodies in Rhesus monkeys. Based on cVNT results, the inactivated vaccine in 0.5 and 1 microg/100 microL doses was able to induce a neutralizing effect against the SARS-CoV-2 virus up to a dilution of 1512 and 11000. The protective efficacy of the vaccine candidate was challenged with 2 x108 PFU of live viruses and confirmed by lung CT scan and histopathological evaluations compared to the control group. Repeated intramuscular injection of the candidate vaccine was generally well-tolerated in Rats and Rhesuses. No significant side effects were observed in rats injected with ten full human doses and in the Rhesus monkeys with three full human doses. Conclusion(s) Based on the findings presented in this study, it is recommended that this vaccine be moved into human testing commencing with a phase I clinical trial.Copyright © 2021 Muslim OT et al.