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: Australia; COVID-19; K18-hACE2 mice; Omicron BA.1; SARS-CoV-2; SARS-CoV-2 variants; ancestral; challenge; coronavirus disease; cross-protection; immunogenicity; mice; neutralizing antibodies; respiratory infections; severe acute respiratory syndrome coronavirus 2; vaccine-preventable diseases; viruses; zoonoses.