“Mucosal vaccines go directly into the mucosal tissue where infection begins – for example, intranasally or via tablets. If they could induce strong enough mucosal immunity, such vaccines could reduce the risk of infection and transmission. That’s often called “sterilizing” immunity.

Development of these vaccines has just received a massive boost. A global consortium is being funded to develop and then run human challenge trials of intranasal or inhaled vaccines in a program called MusiCC.”