Low-dose Ad26.COV2.S protection against SARS-CoV-2 challenge in rhesus macaques.

ABSTRACT: We previously reported that a single immunization with an adenovirus serotype 26 (Ad26)-vector-based vaccine expressing an optimized SARS-CoV-2 spike (Ad26.COV2.S) protected rhesus macaques against SARS-CoV-2 challenge. To evaluate reduced doses of Ad26.COV2.S, 30 rhesus macaques were immunized once with 1 × 10¹¹, 5 × 10¹⁰, 1.125 × 10¹⁰, or 2 × 10⁹ viral particles (vp) Ad26.COV2.S or sham and were challenged with SARS-CoV-2. Vaccine doses as low as 2 × 10⁹ vp provided robust protection in bronchoalveolar lavage, whereas doses of 1.125 × 10¹⁰ vp were required for protection in nasal swabs. Activated memory B cells and binding or neutralizing antibody titers following vaccination correlated with protective efficacy. At subopti

SUBMITTER: He X 

PROVIDER: S-EPMC8166510 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature