Comparable Neutralization of the SARS-CoV-2 Omicron BA.1 and BA.2 Variants

ABSTRACT

The SARS-CoV-2 Omicron variant (B.1.1.529) has three major lineages BA.1, BA.2, and BA.31. BA.1 rapidly became dominant and has demonstrated substantial escape from neutralizing antibodies (NAbs) induced by vaccination2-4. BA.2 has recently increased in frequency in multiple regions of the world, suggesting that BA.2 has a selective advantage over BA.1. BA.1 and BA.2 share multiple common mutations, but both also have unique mutations1 (Fig. 1A). The ability of BA.2 to evade NAbs induced by vaccination or infection has not yet been reported. We evaluated WA1/2020, Omicron BA.1, and BA.2 NAbs in 24 individuals who were vaccinated and boosted with the mRNA BNT162b2 vaccine5 and in 8 individuals who were infected with SARS-CoV-2 (Table S1). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=61 SRC="FIGDIR/small/22270533v1_fig1.gif" ALT="Figure 1"> O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/22270533v1_fig1a.gif" ALT="Figure 1"> View larger version (26K) org.highwire.dtl.DTLVardef@1b39fc8org.highwire.dtl.DTLVardef@1bf16ceorg.highwire.dtl.DTLVardef@7248ecorg.highwire.dtl.DTLVardef@111a215_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO Neutralizing antibody responses to Omicron BA.1 and BA.2. A. Cartoon showing BA.1 and BA.2 mutations in the SARS-CoV-2 Spike. NTD, N-terminal domain; RBD, receptor binding domain; RBM, receptor binding motif; SD1, subdomain 1; SD2, subdomain 2; FP, fusion peptide; HR1, heptad repeat 1; HR2, heptad repeat 2. B. Neutralizing antibody (NAb) titers by a luciferase-based pseudovirus neutralization assay in individuals two weeks following initial BNT162b2 vaccination (Prime), prior to boost (Pre-Boost), and two weeks following the third boost with BNT162b2 (Boost). C. NAb titers in 8 individuals following infection with SARS-CoV-2 Omicron BA.1, of whom 7 were vaccinated. The individual with negative NAb titers was unvaccinated and was sampled 4 days following diagnosis and hospitalization with severe COVID-19 pneumonia. Responses were measured against the SARS-CoV-2 WA1/2020, Omicron BA.1, and BA.2 variants. Medians (red bars) are depicted and shown numerically with fold differences. C_FIG O_TBL View this table org.highwire.dtl.DTLVardef@a84ecborg.highwire.dtl.DTLVardef@1cd2d42org.highwire.dtl.DTLVardef@1567410org.highwire.dtl.DTLVardef@ddcf54org.highwire.dtl.DTLVardef@56b617_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable S1.C_FLOATNO O_TABLECAPTIONStudy population. C_TABLECAPTION C_TBL