SAT and ACT Score Requirements for Vanderbilt University, Nashville, Tennessee.
Type A flu is the most common type of influenza. Type A influenza symptoms include respiratory symptoms like coughing and sneezing and a runny nose, as well as influenza symptoms like headache, muscle aches, and fever. Flu symptoms are similar to the symptoms of a cold, but fever is rare with a cold and common with the flu.
There are four types of influenza viruses: A, B, C and D. Wild aquatic birds â particularly certain wild ducks, geese, swans, gulls, shorebirds and terns â are the natural hosts for most influenza type A viruses. Subtypes of Influenza A Viruses Influenza A viruses are divided into subtypes on the basis of two proteins on the surface of the virus: hemagglutinin (HA) and neuraminidase (NA).