How to Get Silicon Valley’s Anti-Vaxxers to Change Their Minds

There’s been a lot of shaming and blaming of the anti-vaccination crowd in response to the Disneyland measles outbreak (even we did it). And when we released our investigation of vaccination rates at Silicon Valley preschools, people were justifiably angry: Every unvaccinated kid at those schools threatens the greater community’s protection against disease. But yelling at anti-vaxxers won’t change their minds—which is what we need most to prevent more outbreaks. That begs the question: What can turn them around?

After writing about how vaccinated people got measles in California, I read the comments posted about it on Facebook. Among the anti-vax commenters, there were a few science-hating, vitriol-slinging, homeopathy-hawking kooks. But the vast majority were…reasonable. Take this person, for example:

Someone strong enough to get the vaccine (and thus be conferred limited immunity for 2-10 years) is likely strong enough to handle the disease and consequently have real life-long immunity, which is what is really needed for “herd immunity” to actually work.

This person is wrong, of course, but there’s some science—or at least some attempts at using science—in there. It’s worth repeating, clearly: Refusing vaccines is a bad choice, but anti-vaxxers aren’t evil for making that choice. Every parent who turns down a vaccine is simply trying to make the right decision for their kid. As long as that motivation exists, there’s a chance that a parent can be convinced that vaccination is the safest choice—for their child, and those around them.

To figure out how to turn that “no” into a “yes,” it’s important to know how that decision occurred in the first place. As Amy Wallace explained in a WIRED cover story, vaccine refusal comes down to one emotion: fear. Or, in the current environment, the lack of it.

Thanks to the success of vaccination programs, many Americans have never seen a single case of measles—they didn’t get it themselves, and probably don’t know anyone who’s had it. That interferes with how they process fear in two ways.

Number one, we get responses like this one (from that same story, on Facebook):

Measles is not a dangerous disease, it is just a normal childhood disease, it’s safer to get antibodies from the actual virus than from vaccines. Unvaccinated children have higher and stronger immune systems, so they fight it fast…

Measles has, for many, become a hypothetical disease. And a hypothetical disease isn’t scary. “People become desensitized to the seriousness of the disease when they’re not exposed,” says Kristin Hendrix, a pediatric researcher at Indiana University School of Medicine. Measles was eradicated in the US in 2000, so even if you’ve seen a case, you probably haven’t met someone who pulled the short straw: The one person in 10 who gets an ear infection, potentially resulting in deafness, or the one in 20 who gets pneumonia, or the one in 1,000 who develops encephalitis—or dies.

Which leads us to number two. The risk of vaccines—the one in 3,000 chance of seizure for the MMR, or the one in more than a million chance of a serious allergic reaction—starts to seem much bigger in comparison to those fading memories of measles past. “Parents can be scared very easily by hearing about potentially negative consequences,” says Gary Freed, a pediatric researcher at the University of Michigan. And the act of stabbing your kid in the arm with a needle far more immediately threatening than the potential exposure to measles, especially if you’re counting on her not being exposed to the disease in the first place.

My husband nearly died from the tetanus vaccine when he was a kid.

Fear is a powerful, often irrational emotion. No matter how many times you drive home the statistical near-impossibility of a negative vaccine reaction, it’s often overlooked in the face of a personal anecdote. If someone has a relative who had a bad reaction to a vaccine—or even a great-aunt on Facebook whose friend’s daughter became withdrawn after one—the immediacy of that story will carry more cognitive weight than numbers. Humans are big on narrative. Science (usually) is not. So now, medical professionals and researchers must figure out how to use information—cold, impersonal facts—in a way that can counteract the power of that primal (and inaccurate) risk calculation.

That job is far harder than it used to be. Doctors once were the primary source of medical information, but now it’s everywhere online—some of it true, some of it not, and the vast majority somewhere in between. That’s a problem, because humans suffer from a major case of confirmation bias. “We seek out and gravitate toward information that confirms what we know to be true,” says Hendrix. Sometimes confirmation bias is so extreme that it even turns positive messages into negative ones: One paper last year found that while pro-vaccine information corrected some misperceptions about vaccines—like the fallacy that it causes autism—reading it actually made some resolutely anti-vax parents even less likely to vaccinate.

Unfortunately, recent research has shown that presenting provaccine messages and evidence to anti-vaxers only makes them become more ingrained in their misguided beliefs.

Researchers don’t have any great ideas about how to change the “stickiness” of bad information once it gets that distorted. But there’s hope. There always have been a certain number of staunchly anti-vaccine parents—researchers estimate about 2 percent of parents fall into that camp, and that number isn’t changing much. It’s a second group of parents and patients—the so-called vaccine-hesitant—that are the ones fueling the fire of vaccine refusal. But they’re also the ones that still may be open to change.

Doug Opel is a pediatrician at Seattle Children’s Hospital working to target those fence-sitters with individually tailored information. “Parents themselves can have a hard time knowing where they are, or they don’t fully disclose what they think about vaccines in an appointment,” says Opel. “That turns a pediatric appointment into a chess match.”

Opel’s shot at a solution is a 15-question survey that gives parents a score on a scale of 0 to 100—over 50, and you’re much less likely to vaccinate. He’s most interested in targeting parents in that 50-to-80 range, by addressing their specific concerns in one-on-one conversations instead of relying solely on an impersonal Vaccine Information Statement from the CDC.

It’s not an easy job: Any conversation he has with a patient is going head-to-head with personal horror stories from Facebook friends and anti-vaccine celebrities. “We know that personal narratives and anecdotes that are emotionally laden are very persuasive,” says Hendrix, “and that people play into fear-based information more than positive information.”

Read more at Wired Science