I didn't read past the paywall, but it sounded like it would be missing the point a bit in the coverage of the online discourse. Hardcore online anti-vaxxers are either grifters, conspiracy theorists or Darwinists playing dress-up. A Darwinist will point to underlying health issues because they think people dying of preventable diseases is the proper way for society to function. This is frankly a very common view among edgy 15 year old boys that have taken a bio 1 class (I remember having held it myself for a little bit), and as a result, will always have a large number of online proponents. Unless we suddenly stop having kids entirely or something, then the problem would largely go away over the course of a couple decades. This is likely the largest group of voices, at any rate, as its bolstered by other social Darwinists for whom it isn't just a phase.

The grifter makes money off of all this, so of course they'll automatically discredit any threat to their income.

The conspiracy theorist won't really believe anything anyone with any power or authority says, so they're usually a lost cause to everyone outside their own personal circle.

None of these people (except the conspiracy theorist sometimes, ironically) care all that much about the lives of strangers, most especially the edgy teenager. There's a reason he's always telling people to commit suicide as a casual insult. So ... what'd we expect again...? And how much money are we able/willing to invest into education to combat it?

It wouldn't even all require a critical thinking focus, a small tweak to the bio 1 curriculum where we go into a little more depth on evolution factors would probably make a noticeable difference. Push the taxonomy unit off to bio 2 or something to make room, that's not particularly important unless you're planning on continuing in the sciences anyway.