To be fair, every big vaccination event had it's anti vaxers campaigns AFAIK.
We have internet and social networks now, i would say that is the only difference.
With so much information (and misinformation) at your fingertips, it's impossible for most people to really grasp on what data to follow, so obviously, confirmation bias kicks in and you just hold onto the info that tells you, you are right.
With google everyone feels like an expert, you might have never spend more than a couple of classes learning biology but feel no doubt in quoting some paper pretending to understand the data as if you are peer reviewing it.