Influenza Viruses

There are three types of influenza virus that infect humans: A, B and C. Types B and C only affect humans and do not cause pandemics. The type B and C viruses are not further classified into subtypes, but there are different strains of type B

Influenza Type B: Causes seasonal influenza epidemics that are clinically similar but with higher attack rates in children. Clinically, type B infections are indistinguishable from type A infections.
Influenza Type C: These viruses cause only mild disease and are not considered clinically important to diagnose or treat.

> Influenza Type A
> Antigenic Drift and Shift