While if contracted with type B the virus can still be transmitted, but a milder version which is more unlikely to kill. Another big difference between the virus types is type B does not carry any subtypes, so scientist can easily identify the virus. The mildest of all three types of the influenza virus is type C which can also be found only in humans just like type B. Type C generally does not create an epidemic or pandemic like the other two types nor does it weaken a person's immune system or create a respiratory