Immunogenicity and Protective Efficacy of a Trivalent Whole-Virion Inactivated SARS-CoV-2 Vaccine Against Vaccine-Matched Ancestral, Delta, and Omicron BA.5 Variants in K18-hACE2 Mice

Background

Continuous antigenic evolution of SARS-CoV-2 has reduced the effectiveness of vaccines based on a single ancestral strain, highlighting the need for multivalent vaccine strategies. We developed a trivalent whole-virion inactivated vaccine containing ancestral (ERAGEM), Delta, and Omicron BA.5 antigens and evaluated its immunogenicity and protective efficacy in K18-hACE2 transgenic mice.