Viruses
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
By Hazel Yetişkin, Muhammet Ali Uygut, Shaikh Terkıs Islam Pavel and 2 others.
Abstract
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.
Methods
β-propiolactone-inactivated ERAGEM, Delta, and Omicron BA.5 antigens were combined at 1 µg each (3 µg total) with aluminium hydroxide and administered intraperitoneally on days 0 and 21. Variant-specific binding and neutralizing antibody responses were assessed by enzyme-linked immunosorbent assay (ELISA) and microneutralization assays. On day 42, mice were challenged with ERAGEM, Delta, or Omicron BA.5. Survival, body weight, body temperature, infectious viral titers, and viral RNA loads were evaluated.