Even when I was in the Navy I was never allowed to take the flu shot, because of an auto-immune disease and severe anemia. So, either way I lose. I can't take the flu shot because my immune system is so crappy that I end up with the flu a few days after the shot. And I can't avoid catching it because people are gross and can't cover their nose when they sneeze or wash their hands after they use the bathroom and then put their gross germs all over everything they touch.
So hey, it's pretty much a guaranteed 3-4 days of sickness for me, so what's the point?