Influenza is a serious disease.
Influenza is especially dangerous to the elderly, young, and people who have illnesses such as asthma that already compromise their immune system. Flu immunizations can keep people on the job and can keep the flu from being spread. It can have a major impact on readiness. They don't use, as in the past, the whole virus. It's a recombinant vaccine where they use just part of the genetic coat of the virus.