Abstract

Our understanding of the quality of cellular and humoral immunity conferred by coronavirus disease 2019 (COVID-19) vaccination alone versus vaccination plus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough (BT) infection remains incomplete. While the current (2023) SARS-CoV-2 immune landscape of Canadians is complex, in late 2021 most Canadians had either just received a third dose of COVID-19 vaccine, or had received their two dose primary series and then experienced an Omicron BT. Herein we took advantage of this coincident timing to contrast cellular and humoral immunity conferred by three doses of vaccine versus two doses plus BT. Our results show that mild BT infection induces cell-mediated immune responses to variants comparable to an intramuscular vaccine booster dose. In contrast, BT subjects had higher salivary IgG and IgA levels against the Omicron spike and enhanced reactivity to the ancestral spike for the IgA isotype, which also reacted with SARS-CoV-1. Serum neutralizing antibody levels against the ancestral strain and the variants were also higher after BT infection. Our results support the need for vaccines that emulate the enhanced mucosal and humoral immunity induced by Omicron BT without exposing individuals to the risks associated with SARS-CoV-2 infection.One Sentence SummaryOmicron breakthrough elicits cross-reactive systemic and mucosal immune responses in vaccinated adults.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.