Omicron BA.1 and BA.2 neutralizing activity elicited by a comprehensive panel of human vaccines

The SARS-CoV-2 Omicron variant of concern comprises three sublineages designated BA.1, BA.2, and BA.3, with BA.2 steadily replacing the globally dominant BA.1. We show that the large number of BA.1 and BA.2 spike mutations severely dampen plasma neutralizing activity elicited by infection or seven clinical vaccines, with cross-neutralization of BA.2 being consistently more potent than that of BA.1, independent of the vaccine platform and number of doses. Although mRNA vaccines induced the greatest magnitude of Omicron BA.1 and BA.2 plasma neutralizing activity, administration of a booster based on the Wuhan-Hu-1 spike sequence markedly increased neutralizing antibody titers and breadth against BA.1 and BA.2 across all vaccines evaluated. Our data suggest that although BA.1 and BA.2 evade polyclonal neutralizing antibody responses, current vaccine boosting regimens may provide sufficient protection against Omicron-induced disease. ### Competing Interest Statement D.C is an employee of Vir Biotechnology Inc. and may hold shares in Vir Biotechnology Inc. A.C.W and D.V. are named as inventors on patent applications filed by the University of Washington for SARS-CoV-2 and sarbecovirus receptor-binding domain nanoparticle vaccines. The Veesler laboratory has received a sponsored research agreement from Vir Biotechnology Inc. HYC reported consulting with Ellume, Pfizer, The Bill and Melinda Gates Foundation, Glaxo Smith Kline, and Merck. She has received research funding from Emergent Ventures, Gates Ventures, Sanofi Pasteur, The Bill and Melinda Gates Foundation, and support and reagents from Ellume and Cepheid outside of the submitted work. A.S. is a consultant for Gritstone Bio, Flow Pharma, ImmunoScape, Avalia, Moderna, Fortress, Repertoire, Gerson Lehrman Group, RiverVest, MedaCorp, and Guggenheim. SC has consulted for GSK, JP Morgan, Citi, Morgan Stanley, Avalia NZ, Nutcracker Therapeutics, University of California, California State Universities, United Airlines, Adagio, and Roche. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.