Every year a new version of the flu vaccine is made using a mixture of strains. The strains are chosen based on surveillance and analysis by experts from the FDA, WHO. and CDC. For other diseases however, such as varicella (chickenpox), the same vaccine is used continually and repeated vaccinations are not necessary. What do you conclude is the important difference between the influenza virus and the varicella zoster virus with regards to vaccinations?

A) Influenza envelope proteins are bound by IgM, while varicella envelope proteins are bound by IgG.
B) Influenza virus has a much higher mutation rate than varicella, leading to frequent antigen changes in the coat proteins.
C) Varicella is attacked by the innate immune system, while influenza is attacked by the acquired immune system.
D) Influenza virus is transmitted through aerosol droplets in the air, while varicella can be transmitted via skin secretions.