Current COVID-19 vaccines offer great protection from serious illness, but they don't prevent people from becoming infected in the first place. Because of this, researchers have been searching for ways to boost mucosal immunity — the immune response on mucosal surfaces — as this is where the virus is first encountered by the body. Now a team have shown that mucosal immunity can be improved enough to block infection in rhesus macaques by administering booster vaccines directly into their lungs, through inhalation. They hope this could offer a way to stop humans getting COVID-19 in the future.Research Article: McMahan et al.Subscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday. Hosted on Acast. See acast.com/privacy for more information.