Pneumonia is an infection of the lungs, sometimes called a "lower respiratory tract" infection to distinguish it from an ...

Flu symptoms in 2026 include fever, cough, sore throat, body aches, fatigue and more as flu activity rises across the U.S.

“I’m always sick!” and “I can’t believe I have a cold again” are common refrains throughout the fall and winter for many people. It’s not in your head: Respiratory virus season hits some people harder ...

Among the most famous demonstrations of genetic mutations driving infection outcome is severe combined immunodeficiency (SCID ...

The immune system’s first encounter with a virus or vaccine establishes a “starting template” that shapes its response to new ...