SARS-CoV-2 Mucosal Neutralising Immunity after Vaccination

Mucosal vaccines that prevent SARS-CoV-2 infection might provide benefits beyond existing intramuscularly administered vaccines: through enhanced individual-level protection against disease, and population-level reduction of viral carriage and transmission. Secreted neutralising antibodies are most likely to be the crucial effectors for such vaccines generating a mucosal response.1 However, it is unclear to what extent intramuscular administration of SARS-CoV-2 vaccines enhances neutralising antibody titres in the mucosal compartment, nor the breadth of variants that are neutralised.