Substantial Neutralization Escape by the SARS-CoV-2 Omicron Variant BQ.1.1

Abstract

Omicron BA.5 has been the globally dominant SARS-CoV-2 variant and has demonstrated substantial neutralization escape compared with prior variants. Additional Omicron variants have recently emerged, including BA.4.6, BF.7, BA.2.75.2, and BQ.1.1, all of which have the Spike R346T mutation. In particular, BQ.1.1 has rapidly increased in frequency, and BA.5 has recently declined to less than half of viruses in the United States. Our data demonstrate that BA.2.75.2 and BQ.1.1 escape NAbs induced by infection and vaccination more effectively than BA.5. BQ.1.1 NAb titers were lower than BA.5 NAb titers by a factor of 7 in two cohorts of individuals who received the monovalent or bivalent mRNA vaccine boosters. These findings provide the immunologic context for the rapid increase in BQ.1.1 prevalence in regions where BA.5 is dominant and have implications for both vaccine immunity and natural immunity.