Flu facts
What is influenza (flu)? Influenza, commonly called “the flu,” is a lung (respiratory) infection caused by the influenza virus. Although someone with a mild case of flu may have symptoms similar to a cold, most cases of flu are more serious than the common cold. The flu virus changes slightly each year, so each year a new batch of vaccinemust be made. When does flu occur? Flu occurs in the United States most often in the winter. Flu-like symptomsin summer […]