There's no real safe and effective vaccine.

(Oh? What about Polio?)

Well, here’s the problem. Here’s the problem. Yeah, here’s the problem. The polio vaccine contained a virus called simian virus 40. SV40. It’s one of the most carcinogenic materials that is known to man. In fact, it’s used now by scientists around the world to induce tumors and rats and Guinea pigs in labs. But it was in that vaccine, 98 million people who got that vaccine. And my generation got it. And now you’ve had this explosion of soft tissue cancers in our generation that killed many, many, many more people than polio ever did. So if you say to me, “The polio vaccine, was it effective against polio?” I’m going to say, “Yes.” And if say to me, “Did it cause more death than avert?” I would say, “I don’t know, because we don’t have the data on that.