No-Ouch Vaccinations

Some people would love it if vaccinations did not involve needles. And it's possible vaccines for respiratory infections, such as COVID when given through the nose or mouth, may actually be more effective. We have immune cells within the mucous membranes that line the nasal and oral cavities. Priming them with a vaccine could stop the virus where it first enters the body, blocking its spread, and preventing even mild cases of COVID. This would also stop community spread. China, Russia, India, and Iran all have inhaled COVID vaccines and more than one hundred oral or nasal vaccines are in development around the world, but none are available in the US.

Our injected vaccines are great at curbing severe disease but not at preventing mild cases or transmission to others. After a vaccine injection, the activated immune cells circulate through the body but not enough end up in the nose or mouth to prevent infection.

Mucosal vaccines activate tissue resident memory T and B cells that serve as sentinels for future infections. These cells also produce antibodies called IgA in the respiratory tract. Both can immediately respond in future infections. Scientists at Yale found an intranasal vaccine protected mice from a lethal COVID virus dose when an injected one did not.

I look forward to an inhaled COVID booster as a big step toward bringing this virus under control.