On most questions where a majority with authority is facing a minority of dissenters or skeptics, the majority is delusional.
IOW, you are living in the Matrix; much of what you and people believe is fundamentlaly wrong.

Reason 1 is that the majority forms its view by circular reasoning, and rejects any attempt at logical discussion without considering it seriously, so it is prone to delusion.
Reason 2 is a minority wouldn’t be holding out without a good reason, because they are punished for their opposition with scorn and hatred at least. The usual reason they are so stubborn is they are defending rational truth.
Reason 3 is there’s often big money to be made or political power to be gained by influencing the majority opinion. Rationality doesn’t have a press agent, and there’s no money in swaying the minority position.
via…
http://lifeboat.com/blog/2016/07/3-reasons-you-are-living-in-the-matrix-how-to-make-a-red-pill

Basically every paper in the vaccine safety literature is plainly so confounded as to be useless. Since there are no Randomized Placebo Controlled (RPC) trials supporting vaccines, virtually all studies report on the association (or lack thereof) between vaccines and some iatrogenic condition. But parents who believe vaccines made their kids sick, stop vaccinating them, which systematically moves sick or vaccine damaged kids in the studies into the “low vaccine”, “low thimerisol”, or etc. bin. This invalidates most studies supporting safety (and the few remaining ones suck for other reasons). Numerous studies report incredible preventative effects for vaccines, presumably because of this corruption, like having more thimerisol or more MMR’s is strongly preventative of autism and other mental development issues[28][29][30], or like having more vaccines was strongly preventative of atopy, apparently even years before patients got the vaccines[31]. The fact this confounding factor is overlooked demonstrates extreme confirmation bias and is the defining factor of Cargo Cult Science according to R.P. Feynman.[32] The above is point 3 out of 10 from

http://lifeboat.com/blog/2016/06/the-top-ten-reasons-i-believe-vaccine-safety-is-an-epic-mass-delusion