Donald Trump has a long history of promulgating anti-vaccine conspiracy theories (contrary to received wisdom, the anti-vaxx movement draws most of its support from the political right, not hippie liberals), and the tireless leaders of the anti-vaccine movement now claim to have met with Trump and received his promise to ban the most efficient and effective vaccination techniques (nevermind that the president doesn't have the authority to do this).
According to anti-vaxxer Levi Quakenboss, Trump met with Andrew Wakefield — the author of the original, now-debunked study linking autism and vaccinations, who has since had his right to practice medicine revoked over his deliberate research fraud — in August, and promised that a Trump administration would back the ex-doctor's conspiracy theories and limit vaccinations for all American children.
Anti-vaxx leaders have called this "a one issue election" and urged their followers to vote Trump.
So did Donald Trump meet with Andrew Wakefield? Wakefield is a liar, and Quackenboss is deluded, but that doesn't mean they 'aren't telling the truth here. They might be exaggerating or spinning or they might be deluding themselves into believing that Trump cares about their pet conspiracy theories more than he actually does, but it does appear that Trump did meet with a man who is arguably the most famous antivaccine activist in the world.
Donald Trump and disgraced antivaccine "scientist" Andrew Wakefield: Best buds forever?