Very long article here that disappeared behind a paywall before I could get into it
The U.K.’s Delta Surge Is Collapsing. Will Ours?
That's very good article. I was able to read the whole thing. Toward the end, there's an interesting discussion of delivering vaccine via nasal spray (now I'm thinking I might rather have a nasal spray vaccine instead of a booster shot this fall):
"Buried in the CDC presentation was one additional striking fact: that the Delta variant was so much more transmissible, in part,
because of how quickly and prolifically it reproduces and takes root within the nose. What is most remarkable about that is that we have a suite of tools that might help precisely combat that problem, though we aren’t using them: intranasal vaccinations, which are delivered not by jabbing a needle into the muscle of your shoulder but by spraying a mist up your nostril.
This isn’t just a matter of Delta. Back in March, before India’s Delta surge had even begun,
Scientific American published
a sort of intranasal call to arms, by Eric Topol and Daniel P. Oran, under the headline “To Beat COVID, We May Need a Good Shot in the Nose.” As they wrote then, the current class of vaccines being rolled out, all delivered via intramuscular injection, were proving almost miraculously effective at preventing serious disease, hospitalization, and death. “But several coronavirus variants have emerged that could at least partly evade the immune response induced by the vaccines,” they wrote. “These variants should serve as a warning against complacency — and encourage us to explore a different type of vaccination, delivered as a spray in the nose.”
Today, the article reads almost like a Delta prophecy. “Although injected vaccines do reduce symptomatic COVID cases, and prevent a lot of severe illness, they may still allow for
asymptomatic infection,” they wrote. “The reason is that the coronavirus can temporarily take up residence in the mucosa — the moist, mucus-secreting surfaces of the nose and throat that serve as our first line of defense against inhaled viruses.” An intranasal vaccine, they suggested, was the solution: “With a quick spritz up the nose, intranasal vaccines are designed to bolster immune defenses in the mucosa, triggering production of an antibody known as immunoglobulin A, which can block infection. This overwhelming response, called sterilizing immunity, reduces the chance that people will pass on the virus.”
