Until the CDC changed the definition of vaccine in Sept 2021, most vaccines were understood to provide sterilizing immunity against infection, not only "protection" against illness/death.
Intramuscular/serum vaccines cannot stop respiratory infections, by definition. They are non-sterilizing. Only a nasal/mucosal vaccine or nasal infection can provide sterilizing immunity against a respiratory virus.
Intramuscular/serum vaccines cannot stop respiratory infections, by definition. They are non-sterilizing. Only a nasal/mucosal vaccine or nasal infection can provide sterilizing immunity against a respiratory virus.