How about the medical profession? What you may not realize is that one may be sick but not know he's sick. One may have a small, developing tumor of which he's completely unaware, or be in the beginning stages of an infectious disease that has yet to manifest symptoms. In that case, assailing the immune system with an aggressive vaccine could end up causing dire consequences.
That's called asymptomatic. So all vaccinations should be halted because we don't have perfect knowledge? I'm the first to acknowledge what I don't know. You can have MRSA in your nose, and tumors that won't kill you if they are otherwise benign. Somebody usually does a cost/benefit analysis. Who will pay for the unnecessary testing?
I had measles when I was ten years old. I went from 60 to 50 pounds in three weeks in early 1962. While I don't agree with all of the latest vaccination recommendations, docs don't make enough money for all of the headaches.