During flu season, it's important to understand who is at higher risk of getting the flu and what the differences are between Influenza A and Influenza B. The flu, short for influenza, is a respiratory illness caused by a virus that infects the nose, throat, and sometimes the lungs. Symptoms can range from mild to severe and may include fever, cough, sore throat, body aches, and fatigue. The flu is highly contagious and can spread from person to person through droplets when someone with the flu talks, coughs, or sneezes. People of all ages can get the flu, but certain groups are at higher risk of developing complications or severe illness if they become infected. These groups include: Young children: Children under the age of 5, and especially those under 2 years old, are at higher risk of developing complications from the flu. Older adults: Adults over the age of 65 are at higher risk of developing complications from th