First I suggest you avoid the flu shot at all costs. This shot doesn't prevent the flu. It is only made to prevent one strain of the flu. There are many other strains out there that you are susceptible to catching. The flu shot has many many side effects that may or more not affect you...also the long term effects of this shot are not known. What is known though is that aluminum, one of the preservative in this shot is toxic and will build up in the brain and is directly linked to Alzheimer's disease.
Also, something to think about is the fact that not everyone gets the flu and the shot doesn't prevent the flu. What does prevent catching the flu is a healthy immune system. You can simply build your immunity by limitin Sugar intake, getting plenty of sunshine and exercise and taking vitamin c and garlic.