You know what Flu shots are? They basically give you the flu, but its supposed to be a weakened version so that your body can kill it and develop a defense against it.
Personally I never ever get flu shots. I think its stupid. And guess what? I almost never get the flu.
When I do get the flu, it only lasts a day or two. Whereas if I were to get the flu shot, my arm would be killing me for two weeks. Why anyone gets flu shots is a mystery to me. Build up your immune system instead.