The authors of this study has previously 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, they 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 induces neutralizing antibodies and T cell responses and limits or prevents 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.
Hassan, A.O., et al., A single intranasal dose of chimpanzee adenovirus-vectored vaccine protects against SARS-CoV-2 infection in rhesus macaques, Cell Reports Medicine (2021), doi: https://doi.org/10.1016/j.xcrm.2021.100230