But both sides sound as if they have done real science, so a basic understanding of how science is done won’t be enough to tell them apart. You can get anti-vaccine books written in an academic tone with citations. They go through the appearance of presenting evidence. The only difference between the two sides that is visible to an ordinary member of the public is that one side represents “the establishment” and the other side doesn’t.

Even professional scientists have to have a lot of trust in the institutions of science - if I read a paper then unless there is something egregiously wrong, I rely on the journal and the scientific community to check that the authors did what they claimed to do and that they got the results they claim to have.