SARS-CoV-2 Omicron BA.1 Challenge after Ancestral or Delta Infection in Mice

Abstract

We assessed cross-reactivity to BA.1, BA.2, and BA.5 of neutralizing antibodies elicited by ancestral, Delta, and Omicron BA.1 SARS-CoV-2 infection in mice. Primary infection elicited homologous antibodies with poor cross-reactivity to Omicron strains. This pattern remained after BA.1 challenge, although ancestral- and Delta-infected mice were protected from BA.1 infection.

Keywords

• COVID-19
• coronavirus disease
• SARS-CoV-2
• severe acute respiratory syndrome coronavirus 2
• viruses
• respiratory infections