You'll hear me use the phrase a lot. There ARE antivaxxers. They are the leaders of the antivaccine movement, the bloggers, the conspiracy theorists. These are not the "vaccine-averse," "vaccine curious," or "vaccine concerned." They are antivaxxers. 1/ https://twitter.com/ASlavitt/status/1339369587628859397

These days, antivaxxers are the source of much of the misinformation, pseudoscience, quackery, and disinformation that creates the "vaccine-averse" and "vaccine concerned." They are the propagandists. They are the grifters. Many are even true believers. 2/

Trying to persuade an antivaxxer to vaccinate (or even to stop spreading antivax misinformation) is almost impossible. Being antivaccine is part of their identity as much as religion, political beliefs, and other ideologies. Motivated reasoning and confirmation bias rule them. 3/

Antivaxxers are also immersed in the central conspiracy theory of the antivaccine movement, namely that "they" (CDC, FDA, doctors, pharma) "know" that vaccines are harmful and don't work, but "they" are covering up the evidence. They're like QAnon that way. 4/

Moreover, antivaxxers are very good at portraying themselves as not being "antivaccine" but being "pro-" something good, such as freedom, parental rights, "choice," etc. They're "just asking questions." 5/

When skeptics accept their self-portrayal and don't look behind the facade, they win. They can pass themselves off as the "vaccine concerned," even though no amount of persuasion, evidence, or empathy will ever convince them that vaccines are not a toxic eugenics plan. 6/

The key is to learn to be able to tell the difference between antivaxxers and those who are "vaccine concerned" or "vaccine averse" but still reachable. Don't bother with the former other than to show why and how what they're saying is disinformation and pseudoscience. 7/

The idea is to marginalize them, to—if you'll excuse the term—inoculate those susceptible to their message against their disinformation techniques, conspiracy theories, and pseudoscience. Refusing to call them what they are, antivaxxers, hinders that inoculation effort. 8/

Meanwhile, treat the vaccine averse and concerned with respect and empathy as you try to reach them. Understand that they just want what is best for their children (and them) but have been misled. 9/

Now, I will admit that it isn't always easy to tell a true antivaxxer from the stronger vaccine averse. It's a continuum. There is no hard and fast border between the two. There are some techniques that I've found useful, though. 10/

First, when someone says negative things about vaccines, ask them if there are any individual vaccines that they consider safe and effective and would recommend in general. If they say no or dance around the question, they're almost certainly antivaccine. 11/

Another good question: Ask them to list specific pieces of evidence that it would take to convince them that vaccines are safe and effective. You can ask this question for vaccines in general or for an individual vaccine, such as MMR or #CovidVaccine. 12/

If they propose an impossible standard of evidence (e.g., massive RCT evidence that a vaccine is 100% safe and 100% effective PLUS massive epidemiological studies of millions of people with zero adverse reactions), they're very likely antivax. 13/

If they insist on a massive randomized placebo-controlled trial over 20 years showing that vaccines do not cause autism and react negatively if it's pointed out that such a study would be highly unethical, they're antivax. 14/

However, here's perhaps the most useful standard in terms of responses to the question about evidence. If they keep moving the goalposts as you provide evidence that meets each set of standards they answer you with, they are almost certainly antivax. 13/

Again, there's very little point trying to engage with real antivaxxers. The cost in terms of time and effort far outweighs the benefit of the tiny likelihood that you might get them to start to change their minds. 14/

Instead, target the fence-sitters, the "vaccine curious" and averse who might be reachable. To do that, however, you need to know how to distinguish them from antivaxxers. It takes time to develop an accurate "I know one when I see one" instinct about antivaxxers, as I have.15/15

I forgot: One other VERY good indicator of an antivaxxer: The grift. If the person sells "substitutes" for vaccines, woo to treat "vaccine injury," or "alternative vaccine schedules," he is almost always an antivaxxer. 15a/15