The influenza virus is a contagious respiratory illness, but it differs from a cold, according to the CDC. It comes on suddenly with symptoms that include fever or chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches and fatigue. Children may experience vomiting and diarrhea.

Columbia residents needing a flu vaccine should contact a physician or the Columbia/Boone County Public Health Department.