Nasal vaccines could provide better protection against infection by bolstering immunity right where the virus enters the body, but few have made it to human trials in the U.S.
Feb. 24, 2023 by Denise Chow
An experimental nasal vaccine provided strong protection against Covid infection, according to preliminary results from a Phase 1 clinical trial.
The vaccine, developed by a startup called Blue Lake Biotechnology Inc., was found to reduce the risk of symptomatic Covid infections by 86% for three months in people who received it as a booster dose. Existing booster shots in the United States reduce symptomatic infections by 43% in people 18 to 49 over one to two months, according to a study published in November by the Centers for Disease Control and Prevention.
The results from the clinical trial offer an early but tantalizing glimpse at how a next-generation Covid vaccine could be more effective at stopping the coronavirus in its tracks.
Scientists have said nasal vaccines could provide better protection against Covid compared to those that are injected into the arm.
Because these vaccines are sprayed in the nose, they are thought to more readily jump-start the immune system against respiratory viruses. Essentially, nasal vaccines bolster immune protection right where the virus enters the body, setting up a more targeted line of defense.
The idea is to give the immune system a heads-up so that the virus “won’t even have a chance to take hold,” said Dr. Benjamin Goldman-Israelow, an assistant professor of medicine at the Yale School of Medicine, who is not involved with Blue Lake’s clinical trials.
Goldman-Israelow’s own research in animals has shown similarly promising levels of protection. In a study published in October in the journal Science, he and his colleagues demonstrated that a nasal vaccine booster induced a strong immune response in the upper airway and was more effective at blocking Covid infections than vaccines injected intramuscularly.
Despite their promise, progress on nasal vaccines in the U.S. has lagged behind other countries. While several versions of a nasal vaccine are in development, most are in preclinical stages. Aside from Blue Lake’s vaccine, only one other vaccine, from researchers at Mount Sinai in New York City, has reached human trials.
Nasal Covid vaccines have been approved in India, Iran and Russia, and two others are in use in China, along with an inhalable version that was approved in September for use as a booster. But, few details of their efficacy have been publicly released so far.