Study: Bivalent SARS-CoV-2 mRNA vaccines increase breadth of neutralization and protect against the BA.5 Omicron variant. Image Credit: NIAID
Likewise, a previous study showed that mRNA-1273.211 encoding Wuhan-1 and Beta VOC S proteins induced higher neutralizing antibody titers in humans against Beta, Delta, and Omicron BA.1 than the parental mRNA-1273 vaccine. Overall, bivalent vaccines encoding S proteins from ancestral and newly-emerged SARS-CoV-2 VOCs could broaden COVID-19 vaccine-induced immunity.
Study findings The primary vaccination series of all tested vaccines induced robust serum antibody binding responses against S2P, S2P.529, and S2P.045 proteins, although the mRNA-1273.529 and mRNA-1273.045 vaccines had lower titers against non-matched S antigens. However, bivalent vaccines had exceptional neutralization breadth. They potently neutralized Omicron BA.1., BA.4/5, and Wuhan-Hu1 pseudoviruses.