Internal medicine

Virus

Disease

Coronavirus disease 2019 (COVID-19)

Infectious disease (medical specialty)

Outbreak

Neutralization

Antibody

Virology

Immunology

Spike Protein

Neutralizing antibody

2019-20 coronavirus outbreak

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Titer

Medicine

New England Journal of Medicine

To the Editor: In recent months, multiple lineages of the omicron (B.1.1.529)variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged, 1 with subvariants BA.1 and BA.2 showing substantial escape from neutralizing antibodies. 2-5Subvariant BA.2.12.1 is now the dominant strain in the United States, and BA.4 and BA.5 are dominant in South Africa (Fig. 1A).Subvariants BA.4 and BA.5 have identical sequences of the spike protein.We evaluated neutralizing antibody titers against the reference WA1/2020 isolate of SARS-CoV-2 along with omicron subvariants BA.1, BA.2, BA.2.12.1, and BA.4 or BA.5 in 27 participants who had been vaccinated and boosted with messenger RNA vaccine BNT162b2 (Pfizer-BioNTech) and in 27 participants who had been infected with the BA.1 or BA.2 subvariant a median of 29 days earlier (range, 2 to 113) (Tables S1 andS2 in the Supplementary Appendix, available with the full text of this letter at NEJM.org).In the vaccine cohort, participants were excluded if they had a history of SARS-CoV-2 infection or a posi-The New England Journal of Medicine Downloaded from nejm.

Neutralization Escape by SARS-CoV-2 Omicron Subvariants BA.2.12.1, BA.4, and BA.5