A single intranasal dose of chimpanzee adenovirus-vectored vaccine protects against SARS-CoV-2 infection in rhesus macaques

Hassan, Ahmed O.; Feldmann, Friederike; Zhao, Haiyan; Curiel, David T.; Okumura, Atsushi; Tang-Huau, Tsing-Lee; Case, James Brett; Meade-White, Kimberly; Callison, Julie; Lovaglio, Jamie; Hanley, Patrick W.; Scott, Dana P.; Fremont, Daved H.; Feldmann, Heinz; Diamond, Michael S.

The deployment of a vaccine that limits transmission and disease likely will be required to end the Coronavirus Disease 2019 (COVID-19) pandemic. We recently described the protective activity of an intranasally-administered chimpanzee adenovirus-vectored vaccine encoding a pre-fusion stabilized spike (S) protein (ChAd-SARS-CoV-2-S) in the upper and lower respiratory tract of mice expressing the human angiotensin-converting enzyme 2 (ACE2) receptor. Here, we show the immunogenicity and protective efficacy of this vaccine in non-human primates. Rhesus macaques were immunized with ChAd-Control or ChAd-SARS-CoV-2-S and challenged one month later by combined intranasal and intrabronchial routes with SARS-CoV-2. A single intranasal dose of ChAd-SARS-CoV-2-S induced neutralizing antibodies and T cell responses and limited or prevented infection in the upper and lower respiratory tract after SARS-CoV-2 challenge. As this single intranasal dose vaccine confers protection against SARS-CoV-2 in non-human primates, it is a promising candidate for limiting SARS-CoV-2 infection and transmission in humans.