Mucosal vaccine-induced cross-reactive CD8⁺ T cells protect against SARS-CoV-2 XBB.1.5 respiratory tract infection.

ABSTRACT: A nasally delivered chimpanzee adenoviral-vectored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (ChAd-SARS-CoV-2-S) is currently used in India (iNCOVACC). Here, we update this vaccine by creating ChAd-SARS-CoV-2-BA.5-S, which encodes a prefusion-stabilized BA.5 spike protein. Whereas serum neutralizing antibody responses induced by monovalent or bivalent adenoviral vaccines were poor against the antigenically distant XBB.1.5 strain and insufficient to protect in passive transfer experiments, mucosal antibody and cross-reactive memory T cell responses were robust, and protection was evident against WA1/2020 D614G and Omicron variants BQ.1.1 and XBB.1.5 in mice and hamsters. However, depletion of memory CD8⁺ T cells before XBB.1.5 challenge resulted in loss

SUBMITTER: Ying B 

PROVIDER: S-EPMC10907304 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature