The flu season is rapidly approaching, and as you may already know, swine flu is already here. There was a case of it at PAX, and a friend of mine at Gnomedex had it as well. Some doctors I know are seeing far more flu cases than usual for this time of year, and so when the real season hits we may be in for quite a ride.
I strongly urge you to read this influenza primer by my friend Dr. Joe Albietz. I've linked to his stuff before; he's a pediatrician and skeptic who cares very deeply about the health of children. He is a clear and thoughtful writer, and his primer will give you a huge amount of basic info on the "regular" flu as well as the swine flu, and why he's worried about it.
The antivax folks have been spreading their usual manure about the swine flu, and (as also usual) giving bad and frankly dangerous advice about it. Go read what Dr. Albietz has to say, and then talk to your own doctor. This is a serious matter, and we need to rely on serious professionals.