Covid-19 vaccines have rapidly altered our relationship with SARS-CoV-2, turning a dangerous infection into something akin to the common cold for many vaccinated people who contract it. But while these vaccines are great at protecting against severe illness and death, they cannot stop vaccinated people from contracting the virus and experiencing mild symptoms.
If we want to prevent mild Covid infections, we’re going to need vaccines that protect us where infections start: in the mucus membranes of the nose, mouth, and throat. And for that, we’re likely going to need intranasal vaccines.