I had a chat with my parents about this one actually. My father has been anti-drug for anything for ages. Except for his heart attack. He let them do what they needed to do for that, but otherwise, he avoids prescriptions as much as possible.
In 1999, I went home to visit my parents for Christmas and being the thoughtful, caring daughter I am, I brought along a flu bug with me. I was pretty darn sick with the flu as I recall, but I got over it without much trouble (the flight back with stuffed up head, NOT GOOD.. my ears didn't pop for days after!).
My parents on the other hand, got hit wickedly hard with this bug that I brought home (my picture of health brother didn't get sick what so ever, go figure). End result was my mother collapsing on the floor one evening, my father calling 911 and both of them being rushed to the hospital in separate ambulances (he was dreadfully sick as well, but seeing my mother that ill put him into a state of panic and anxiety).
Since then, they've both gotten the flu shot annually and neither of them have had the flu since.
Hearing the story has somewhat changed my opinion of the shot, or got me thinking about getting it. Especially since my father swears by it now, and when he swears by something in the medical world, you know it's good.