Immunogenicity and protective efficacy of BBV152: a whole virion inactivated SARS CoV-2 vaccine in the Syrian hamster model

Abstract The availability of a safe and effective vaccine would be the eventual measure to deal with SARS-CoV-2 threat. Here, we have developed and assessed the immunogenicity and protective efficacy of an inactivated SARS-CoV-2 vaccine (BBV152) in hamsters. Three dose vaccination regime with three formulations of BBV152 induced significant titres of SARS-CoV-2 specific IgG and neutralizing antibodies. The formulation with imidazoquinoline adsorbed on alum adjuvant remarkably generated a quick and robust immune response. Th1 biased immune response was demonstrated by the detection of IgG2 antibodies. Post-SARS-CoV-2 infection, vaccinated hamsters did not show any histopathological changes in the lungs. The protection of the hamsters was evident by the rapid clearance of the virus from lower respiratory tract, reduced virus load in upper respiratory tract, absence of lung pathology and robust humoral immune response. These findings confirm the immunogenic potential of BBV152 and further protection of hamsters challenged with SARS-CoV-2.