California is currently in the midst of a rapidly expanding measles outbreak that began with visitors to Disneyland (not so magical anymore, eh?) and has since spread to the broader community, sickening 51 people so far. Officials have said a lot of the cases emerged because the kids were unvaccinated, and in San Diego alone, nine of the 10 kids who became sick hadn’t gotten a measles vaccine. It’s not hard to see why this happened when you consider that the number of parents opting out of vaccinating their kids has more than doubled since 2007.

The consequences of neglecting a vaccination schedule have appeared time and again. In 2010, for example, the worst pertussis (whooping cough) outbreak in 60 years hit over 9,000 people and killed 10 infants — the majority of those hospitalized were infants under 3 months old who hadn’t yet been vaccinated. But many parents continue to opt out due to fear of side effects from chemicals in the vaccine or the belief that a child’s immune system can’t handle the deactivated virus, among other myths they continue to believe are true. The truth is vaccines are generally safe. They haven’t been proven to cause autism, they won’t give you the flu, and none of this is a conspiracy.

In fact, skipping out on a vaccine not only puts that child at risk of developing a disease but also kids and adults around him, including his parents. Amy Parker, who wasn’t vaccinated as a child, wrote in an article for Slate that she’s seen “more people who have experienced complications from preventable childhood illnesses than I have ever met with complications from vaccines.” These complications included deafness from measles, vision loss from rubella, pneumonia from chickenpox, and death from meningitis.

Moreover, communities with lower rates of vaccinations tend to be clustered together, making them susceptible to outbreaks of these diseases. When that happens, even those who were vaccinated can’t stop the disease from spreading because there needs to be a certain number of people vaccinated — a concept called “herd immunity.” For communities with an outbreak of pertussis or measles, 92 percent of kids must be immunized to stop the disease.

Knowing all this, how do we convince a group of parents resolved to avoid vaccines that they’re safe?

A child in Guinea suffers from measles in 2009. Julien Harneis, CC BY-SA 2.0

The Impenetrable Wall Anti-Vaxxers Built

Firstly, it’s important to note that the vast majority of American parents vaccinate their kids. Upwards of 95 percent of parents keep a schedule of vaccinations. Of the remaining five percent or so who don’t vaccinate their kids, less than one percent actively works against vaccines. This small group, known as anti-vaxxers, has been especially loud.

In a 2004 paper titled “Vanishing Vaccinations: Why Are So Many Americans Opting Out of Vaccinating Their Children?” law Professor Steve Calandrillo wrote, “Vaccines are becoming a victim of their success — many individuals have never witnessed the debilitating diseases that vaccines protect against, allowing complacency toward immunization requirements to build.” On autism, he notes that “the Internet worsens fears regarding vaccination safety, as at least a dozen websites publish alarming information about the risks of vaccines.”

Some parents eat this false information up without looking back. Others believe a healthy diet, including non-GMO food and lots of vitamins and minerals, as well as exercise will keep their kids disease free — this was the case for Parker when she was growing up. Under these assumptions, these parents then sign away personal and religious exemption forms, eliminating the requirement for their kids to be vaccinated when beginning kindergarten.

Convincing these parents isn’t as easy as showing them information on the safety of vaccines; a study from last year showed us that. Published in the journal Pediatrics, researchers from Dartmouth College surveyed 1,759 parents with at least one child on their beliefs regarding vaccines. Then, in a follow-up survey, they showed the parents one of four messages about vaccine effectiveness and the importance of the MMR vaccine for measles, mumps, and rubella. One of the messages was about the autism myth, with multiple links to studies disproving it. Another one listed the many complications that can arise from the diseases, while a third one was a true story about a 10-month-old boy who contracted the disease while inside his pediatrician's office. The last one showed the parents images of children who had contracted the preventable diseases.

These messages, specifically the ones that listed complications and showed images, ended up having a “backfire” effect, reinforcing parents’ beliefs in avoiding vaccines. After seeing these messages, the number of parents who said getting an MMR vaccine led to serious side effects rose from 7.7 percent to 13.8 percent. Looking at the images also increased parents’ beliefs that vaccines caused autism. When it came to the autism message, some parents were actually convinced vaccines didn’t cause autism; however, the number of parents who said they wouldn’t get their child vaccinated still increased.

Speaking about the messages they used, researcher Brendan Nyhan told Mother Jones other messages should to be tested, too. “I don't think our results imply that they shouldn't communicate why vaccines are a good idea,” he said. “But they do suggest that we should be more careful to test the messages that we use, and to question the intuition that countering misinformation is likely to be the most effective strategy.”

If Hard Facts Won’t Convince Them, What Will?

It actually makes complete sense that research won’t convince anti-vaxxers. After all, fighting fire with fire never works; it only ignites more fire. How? In his book The Political Brain, psychologist Drew Westen wrote about a study in which his team gathered supporters of both 2004 presidential candidates George W. Bush and John Kerry, and showed them video footage of their preferred candidate contradicting themselves. The scientists performed MRI scans on their brains while they watched these videos, which showed that as soon as they realized the videos challenged their worldviews, the areas of their brains responsible for reasoning and logic went dormant, Time reported. At the same time, the areas of their brain responsible for a fight-or-flight response activated. 

This innate reaction is the reason we need to look at our approach in a different way. For that we can look to studies on homophobia and abortion.

Michael LaCour, a doctoral candidate at the University of California, Los Angeles, and his team trained lesbian, gay, bisexual, and transexual people to canvass voters in strongly homophobic neighborhoods. They spoke about gay marriage for about 20 minutes, listening to the stories of the voters and telling their own. LaCour’s team found that LGBT canvassers were far more successful at changing voters’ minds about gay marriage than heterosexual canvassers. Their conversations were so strong, in fact, that voters’ still supported same-sex marriage nine months later, and their beliefs had even spilled over to members of the household. Interested in how their experiment could apply to other issues, they sent women out to speak about their abortions to pro-lifers. Again, they were able to change people’s minds.

It’s possible that this method, or a form of it, could work for anti-vaxxers as well. Voices for Vaccines, a parent-driven organization that supports immunization has already started down this path. “We work hard at Voices for Vaccines to get the 90 percent of parents who vaccinate to speak up, because evidence shows that parents can sway the opinions of other parents about vaccines before a provider ever has a chance to bring up immunization in a well-child check-up,” Karen Ernst, the organization’s director, told Medical Daily in an email.

Nurse giving baby the rotavirus vaccine. ChameleonsEye /

Ernst pointed to a study published last year that found 95 percent of parents consulted with people they knew before deciding whether to vaccinate their kids. More importantly, the results showed that parents whose social networks supported vaccines — 87 percent of the people in their network were in favor of vaccines —  were more likely to get their children vaccinated. On the opposite side of that, parents whose social networks said to ignore CDC guidelines — 72 percent of the people in their network said this — were more likely to skip vaccinations. In other words, we may be able to influence anti-vaxxers by influencing the people that influence them.

This level of communication can also be applied to the community, Ernst says. “Vaccinating needs to be seen as a shared community value. Communities value litter-free neighborhoods and do not shy away from promoting this value. Communities also need to come together to say that vaccinating children is important. Parents should be proud that they have protected their children against preventable disease and should let others know that they are doing their part to keep outbreaks out of their communities.”

To Ernst, the effects of parent-to-parent and community communication are clear. She says anti-vaxxers who changed their minds tell stories, “almost universally,” about how someone they knew took the time to convince them they should vaccinate their children.

Tighter Requirements

Unfortunately, parent-to-parent communication is only one piece to the puzzle. States need to implement tighter requirements for kids entering kindergarten. In California, the law requires kindergartners to be vaccinated against measles, mumps, rubella, polio, pertussis, hepatitis B, chickenpox, diphtheria, and tetanus. Yet, it’s easy to get a non-medical exemption based on religious and personal beliefs — in some parts of northern California, as many as 20 percent of kindergarteners had personal belief exemptions for vaccines in 2013.

Those exemptions are easy to get in other parts of the country as well. Some states only require checking a box and signing the form, while other, more strict states, require a doctor’s note. Only 18 states require a notarized doctor’s note and letter of explanation — a lengthier process that may deter some parents. It’s important for states to implement tighter regulations. In a 2012 study, researchers at Emory University found that states with easier requirements had exemption rates 2.3 times higher than in states with the strictest requirements.

It’s possible that by combining both community and tighter requirements, we can sway the parents who aren’t necessarily anti-vaxxers, but haven’t yet vaccinated their kids, to get their kids to a doctor’s office. By doing this, we will not only save communities from terrible outbreaks but also spare children the pain and suffering that comes with childhood diseases.

“If you’ve never had these illnesses, you don’t know how awful they are. I do,” Parker wrote. “Pain, discomfort, the inability to breathe or to eat, or to swallow, fever and nightmares, itching all over your body so much that you can’t stand lying on bedsheets, losing so much weight you can’t walk properly, diarrhea that leaves you lying prostrate on the bathroom floor, the unpaid time off work for parents, the quarantine, missing school, missing parties, the worry, the sleepless nights, the sweat, the tears, the blood, the midnight visits to the emergency room, the time sitting in a doctor’s waiting room on your own because no one will sit near you because they’re rightfully scared of those spots all over your face.”