Evaluation of Safety and Immunogenicity of an Adjuvanted, TH-1 Skewed, Whole Virion Inactivated SARS-CoV-2 Vaccine - BBV152

Ganneru, Brunda; Jogdand, Harsh; Dharam, Vijaya Kumar; Reddy, Narasimha; Prasad, Sai D; Vellimudu, Srinivas; Ella, Krishna M; Ravikrishnan, Rajaram; Awasthi, Amit; Jose, Jomy; Rao, Panduranga; Kumar, Deepak; Ella, Raches; Abraham, Priya; Yadav, Pragya; Sapkal, Gajanan N; Shete, Anita; Desphande, Gururaj Rao; Mohandas, Sreelekshmy; Basu, Atanu; Gupta, Nievedita; Mohan, Krishna Vadrevu

We report the development and evaluation of safety and immunogenicity of a whole virion inactivated SARS-COV-2 vaccine (BBV152), adjuvanted with aluminium hydroxide gel (Algel), or a novel TLR7/8 agonist adsorbed Algel. We used a well-characterized SARS-CoV-2 strain and an established vero cell platform to produce large-scale GMP grade highly purified inactivated antigen, BBV152. Product development and manufacturing were carried out in a BSL-3 facility. Immunogenicity was determined at two antigen concentrations (3g and 6g), with two different adjuvants, in mice, rats, and rabbits. Our results show that BBV152 vaccine formulations generated significantly high antigen-binding and neutralizing antibody titers, at both concentrations, in all three species with excellent safety profiles. The inactivated vaccine formulation containing TLR7/8 agonist adjuvant-induced Th1 biased antibody responses with elevated IgG2a/IgG1 ratio and increased levels of SARS-CoV-2 specific IFN-{gamma}+ CD4 T lymphocyte response. Our results support further development for Phase I/II clinical trials in humans.