We evaluated neutralising antibody titres against wild type (WT) SARS-CoV-2 and four Omicron vari­ants (BA.1, BA.2, BA.5 and BA.2.75) in fully vaccinated (three doses of Comirnaty vaccine) healthcare workers (HCW) in lsrael who had breakthrough BA.1/BA5 infec­tions. Omicron breakthrough infections in vaccinated individuals resulted in increased neutralising antibod­ies against the WT and Omicron variants compared with vaccinated uninfected HCW. HCW who recovered from BA.1 or BA.5 infections showed similar neutralis­ing antibodies levels against BA.2.75.

Euro Surveill
Atari Nofar, Kliker Limor, Zuckerman Neta, Elkader Bayan Abd, Weiss-Ottolenghi Yael, Mendelson Ella, Kreiss Yitshak, Regev-Yochay Gili, Mandelboim Michal.