In the realm of medical advancements, a universal vaccine that can protect against any pathogen has long been a Holy Grail—and about as elusive as a mythological vessel. But Stanford Medicine researchers and collaborators have taken an astonishing step forward in that quest, surprising even themselves.

In a new study in mice, they have developed a universal vaccine formula that protects against a wide range of respiratory viruses, bacteria and even allergens. The vaccine is delivered intranasally—such as through a nasal spray—and provides broad protection in the lungs for several months.

In the study, published in Science, researchers show that vaccinated mice were protected against SARS-CoV-2 and other coronaviruses, Staphylococcus aureus and Acinetobacter baumannii (common hospital-acquired infections), and house dust mites (a common allergen).