Most vaccines—and boosters—are injected directly into muscle tissue, usually in the upper arm, to kickstart the body’s immune system in the fight against disease. But for respiratory diseases like COVID-19, it can be important to have protection right where the virus enters: the respiratory tract.
In a new study, Yale researchers have found that nasal vaccine boosters can trigger strong immune defenses in the respiratory tract, even without the help of immune-boosting ingredients known as adjuvants. The findings, researchers suggest, may offer critical insights into developing safer, more effective nasal vaccines in the future.
“Our study shows how a simple viral protein antigen can boost respiratory tract immune responses against viruses,” said Akiko Iwasaki, Sterling Professor of Immunobiology at Yale School of Medicine (YSM) and senior author of the study. “These data imply that viral proteins in nasal spray may be used as a safe way to promote antiviral immunity at the site of viral entry.”