AUTHOR=Lapointe Hope R. , Mwimanzi Francis , Cheung Peter K. , Sang Yurou , Yaseen Fatima , Kalikawe Rebecca , Datwani Sneha , Waterworth Rachel , Umviligihozo Gisele , Ennis Siobhan , Young Landon , Dong Winnie , Kirkby Don , Burns Laura , Leung Victor , Holmes Daniel T. , DeMarco Mari L. , Simons Janet , Matic Nancy , Montaner Julio S.G. , Brumme Chanson J. , Prystajecky Natalie , Niikura Masahiro , Lowe Christopher F. , Romney Marc G. , Brockman Mark A. , Brumme Zabrina L. TITLE=Serial infection with SARS-CoV-2 Omicron BA.1 and BA.2 following three-dose COVID-19 vaccination JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.947021 DOI=10.3389/fimmu.2022.947021 ISSN=1664-3224 ABSTRACT=

SARS-CoV-2 Omicron infections are common among individuals who are vaccinated or have recovered from prior variant infection, but few reports have immunologically assessed serial Omicron infections. We characterized SARS-CoV-2 humoral responses in an individual who acquired laboratory-confirmed Omicron BA.1.15 ten weeks after a third dose of BNT162b2, and BA.2 thirteen weeks later. Responses were compared to 124 COVID-19-naive vaccinees. One month post-second and -third vaccine doses, the participant’s wild-type and BA.1-specific IgG, ACE2-displacement and virus neutralization activities were average for a COVID-19-naive triple-vaccinated individual. BA.1 infection boosted the participant’s responses to the cohort ≥95th percentile, but even this strong “hybrid” immunity failed to protect against BA.2. Reinfection increased BA.1 and BA.2-specific responses only modestly. Though vaccines clearly protect against severe disease, results highlight the continued importance of maintaining additional protective measures to counteract the immune-evasive Omicron variant, particularly as vaccine-induced immune responses naturally decline over time.