Influence of vaccination and prior immunity on the dynamics of Omicron BA.1 and BA.2 sub-variants
Résumé
The B.1.1.529 SARS-CoV-2 lineage, named Omicron, was recently divided into three lineages (BA.1, BA.2 and BA.3). BA.1 and BA.2 are much more dominant than BA.3. BA.1 could cause breakthrough infections in highly immune populations [1]. Preliminary studies indicate that BA.2 can readily overcome the immunity provided by vaccination and/or infection with an earlier variant. We used data for the French city of Toulouse to evaluate the impact of the proportions of the BA.1 and BA.2 variants in positive-testing samples and the impact of vaccination on SARS-CoV-2 proliferation.