Does Previous SARS-CoV-2 Infection Protect Against Omicron BA.4 and BA.5?

Pre-Omicron infection provided modest protection against BA.4 and BA.5 reinfection; protection was stronger after prior infection with a post-Omicron subvariant.

Omicron BA.4 and BA.5 subvariants have spread rapidly and widely despite substantial population immunity against SARS-CoV-2 from prior infections and vaccination. To estimate the effectiveness of previous SARS-CoV-2 infection against reinfection with Omicron BA.4 and BA.5, investigators used the Qatar national SARS-CoV-2 database in a test-negative, case-control study. They matched cases (positive tests) and controls (negative tests) 1:5 based on factors such as age, sex, nationality, underlying medical conditions, and calendar week. They estimated effectiveness using two sets of cases: those identified with S-gene target failure (a proxy for BA.4 or BA.5 infection), and all cases diagnosed between June 8 and July 28, 2022 (when BA.4 and BA…

Reviewing Author

Mary E. Wilson, MD

Disclosures

Consultant/Advisory BoardOneHealthTrust (formerly Center for Disease Dynamics, Economics, and Policy); Global Health Institute, University of Wisconsin

RoyaltiesUpToDate

Editorial BoardsJournal of Travel Medicine

Mary E. Wilson, MD

Disclosures

Consultant/Advisory BoardOneHealthTrust (formerly Center for Disease Dynamics, Economics, and Policy); Global Health Institute, University of Wisconsin

RoyaltiesUpToDate

Editorial BoardsJournal of Travel Medicine

Does Previous SARS-CoV-2 Infection Protect Against Omicron BA.4 and BA.5?

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Reviewing Author