Type C flu. Influenza C viruses are also found in people but are milder than type A or B. People generally don't become very ill from type C flu viruses, and this type doesn't cause epidemics.

Influenza is a common respiratory virus that is categorized into four types: A, B, C and D. Type C only causes mild infections and type D is not believed to infect humans.

There are also two other types of influenza – C and D – but we don’t worry about them as much. Influenza C typically causes mild illness and doesn’t cause widespread epidemics, the CDC ...

Influenza A is further divided into subtypes. You may have heard of H1N1 or H3N2 – those are the two dominant types of influenza A circulating right now, according to the CDC.

Influenza A is further divided into subtypes. You may have heard of H1N1 or H3N2 – those are the two dominant types of influenza A circulating right now, according to the CDC.