Scientists create universal nasal spray vaccine that protects against COVID, flu, and pneumonia

Scientists at Stanford Medicine have unveiled a bold new kind of “universal” vaccine that could one day protect against everything from COVID-19 and the flu to bacterial pneumonia and even common allergens. Instead of targeting a specific virus or bacterium, the nasal spray vaccine supercharges the lungs’ own immune defenses, keeping them on high alert for months. In mice, it slashed viral levels, prevented severe illness, and even blocked allergic reactions.