[Note: After writing this up initially but before posting it, I saw that Steve Novella has also commented on this, and said much of the same thing I did, but in more detail and with more background. Since I spent the time writing this already, I'll keep it as is, but you should go read what he wrote too!]
Bill Maher is hailed by many as a skeptic, but I disagree with that. He is an atheist, and he has some salient points to make about religion and beliefs. However, he is by no means a skeptic when it comes to matters medical. He rails against "western medicine" (what I prefer to call, simply, medicine), thinks vaccines are dangerous, and buys into a lot of nonsense about vaccinations that is known to be wrong. Note that a denier is not the same thing as a skeptic; go read what Orac has to say about Maher to see how the Real Time host misses the mark by miles in his medical beliefs. You may also guess that I have little love for ex-Senate Majority Leader (and doctor) Bill Frist, who claimed he would never diagnose someone without seeing them first, but then proceeded to do just that on the Senate floor about Terry Schiavo (and get it completely wrong). In my opinion, he let politics trump medicine at that time. But sometimes medicine wins out: Frist schools Maher on the swine flu on Real Time, with Frist telling Maher point blank that he's wrong. This is worth watching. Frist is correct, the things Maher says about vaccines are dead wrong. I wonder if Maher will now do the research instead of just continuing to buy into his flawed belief system? Tip o' the syringe to BABloggee Peter Beattie.