I suppose one more dangerous thing with this, could be how popular anti vaccination ideas could become, when the anti-vaxxers start saying that vaccine is live virus
My variolation example above was only a very specific, very antique context of something that did involve live virus but wasn't considered true vaccination as we use it today. However, even today the basic reality is that some vaccines do involve live viruses or other pathogens in a weakened state. This doesn't make them dangerous in any general sense.
And that live pathogens are sometimes used should be known and discussed for the sake of clinical honesty and public health transparency. Either way, for any deeply dedicated anti-vaxxer, it probably wouldn't matter what they hear from even the best source. Once one's fixation on a concept becomes emotional or ideological, the subtleties and details of explaining contrary details stop mattering to them.
And that live pathogens are sometimes used should be known and discussed for the sake of clinical honesty and public health transparency. Either way, for any deeply dedicated anti-vaxxer, it probably wouldn't matter what they hear from even the best source. Once one's fixation on a concept becomes emotional or ideological, the subtleties and details of explaining contrary details stop mattering to them.