I used to get it yearly, and then there was the "shortage". While I could have had it administered by my girfriend, I opted out for the sake of the children, elderly, etc. I guess I was just having one of those "for the good of everyone else" days that I have once or twice a year.
Expect that it is going to feel a little "funny" (read: stings like crap) and that you may feel a little "off" (read: like you're starting to get the flu) for a day or two. I didn't get the flu - like symptom so much but others I know didn't feel to well for a little while afterward. It wasn't bad, and certainly better than getting the flu. Damn I hate the flu.