For decades, scientists have dreamed of creating a universal vaccine capable of protecting against many different pathogens. The idea has often been compared to a Holy Grail of medicine — a goal that seemed almost impossible to achieve.

Now, researchers at Stanford Medicine and their collaborators say they may have taken a major step toward that vision. In a study conducted in mice, the team developed an experimental vaccine designed to defend against a wide variety of respiratory threats, including viruses, bacteria, and even allergens. The vaccine is administered through the nose — such as with a nasal spray — and produced broad immune protection in the lungs that lasted for several months.

The findings, published in Science, showed that vaccinated mice were protected from SARS-CoV-2 and other coronaviruses, as well as from Staphylococcus aureus and Acinetobacter baumannii (common hospital-acquired infections). The animals were also shielded from house dust mites (a common allergen). According to Bali Pulendran, PhD, the Violetta L. Horton Professor II and professor of microbiology and immunology, who served as senior author of the study, the vaccine has demonstrated protection against an unusually wide range of respiratory dangers tested so far.

If future research confirms these results in people, the approach could eventually replace several yearly vaccines for seasonal respiratory infections and also serve as a rapid defense against emerging pandemic viruses.