The skin microbiome plays an important role in health and disease. Researchers have now substantiated that certain skin bacteria can protect us from the sun’s ultraviolet (UV) radiation specifically by metabolizing cis-urocanic acid using an enzyme called urocanase. This enables the skin's ability to fine-tune how it responds to UV radiation The findings of the study in the Journal of Investigative Dermatology, published by Elsevier, provide a striking case study that demonstrates the ability of the skin microbiome to remodel host immune functions.

New Haven, Conn. — 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 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.