If you are over 50, the risks associated with getting the flu (e.g., being exposed to MRSA in a hospital, pneumonia, etc) are far greater than the risks from the vaccination itself.
Doesn't that depend on circumstances? I don't work. If I go to a movie or a store, it's early in the day when the air has cleared and it's not crowded. I've figured out a really good diet. I have plenty of liquids. I don't go into overcrowded places with bad ventilation.
I figure I've cut the risk of getting the flu (which is never 0) down to less than the risk from a flu shot.
If your sick the worst place to be is in a hospital.