As more people around the world get their hands on COVID-19 Vaccines, what we should have understood from the start is becoming clear. Vaccines that are injected into arm muscles are unlikely to protect our nasal passages from roving SARS-CoV-2 viruses for very long, even if they do a fantastic job protecting our lungs. If we want Vaccines to protect our upper respiratory tracts, we may need intranasal Vaccines, which are administered through the nose.
Is it possible to make them? Probably. If they are created, will they do what we want them to do? Possibly. Is there still room for this type of next-generation product, given the unprecedented number of COVID vaccinations now in use? Potentially. Is it going to be difficult to get them through the development process? Likely. A rudimentary understanding of immunology would be beneficial in understanding the issues at hand.
This is referred to as “sterilising immunity.” There’s no reason to expect that intranasal Vaccines will completely prevent illness, but doctors believe they could perform a better job than current Vaccines by better protecting the nose and throat mucus membranes. Existing vaccinations, according to Florian Krammer, a vaccinologist at Mount Sinai Hospital’s Icahn School of Medicine, certainly elicit high enough levels of circulating antibodies early after immunisation that some of them end up in the nose and throat mucous membranes.