I’ve been writing about the antivaccine movement for a long time. The reasons are many, but they boil down to a handful. First of all, it interests me. It interests me as an example of pseudoscience and quackery, how it spreads, and how antiscience cranks attack science. More importantly, it’s dangerous. The antivaccine movement is a threat to public health, which is why it’s important to study its origins, the methods its members use to attack vaccines, the misinformation it spreads, and how it spreads that misinformation. As a result, I’ve been consistently vilified and attacked by antivaccine cranks, starting with J.B. Handley and most recently finishing up with a hilariously inept attempt at a slime job by our conspiratorial-minded young epidemiologist wannabe Jake Crosby, who seems to think he’s capable of making me squirm. Well, perhaps he is—in disgust and desire to hie myself out of his presence as fast as possible—but when it comes to “proving me wrong,” well, not so much. Still, it is amusing to see that everybody’s favorite over-the-top homeopath Dana Ullman made an appearance to congratulate Jake. (Hint to Jake: When Dana Ullman thinks you’ve done a good job, you really do need to take a long, hard look at yourself and ask yourself if maybe—just maybe—you’ve taken the wrong path.) Perhaps the most hilarious thing of all was a comment by someone by the ‘nym of Otto who in response to the part where I asked Jake if he had ever published in the biomedical literature before responded:
JAKE, you are published at AoA all the time… that is a few steps above most medical publications.
Yes, that’s right. Let that soak into your brain for a moment, and try not to laugh too hard. I failed. Fortunately, to distract me from Jake’s silliness, I came across a real publication that caught my eye because it simultaneously suggests why the antivaccine movement is so dangerous while suggesting why it is so important to counter the misinformation, pseudoscience, and lies promoted by antivaccinationists. Basically, it’s a study of factors that affect parents who decide not to vaccinate and how they come to their decisions. Specifically, it’s about the effect of social networks on vaccination decisions, both pro and con. It’s a study that made the news in reports in TIME and U.S. News and World Report. The study itself, by an anthropologist Emily K. Brunson, was published online in Pediatrics and is entitled The Impact of Social Networks on Parents’ Vaccination Decisions. It consists of a survey of around US-born, first-time parents with children aged ≤18 months in King County, Washington. To give you an idea what sort of environment this county is, it’s worthwhile to look at this news report:
At her son’s preschool near Seattle, Robin Haight is a foot soldier in the vaccine wars. She arranged for a pediatrician to speak about vaccines at the home of a school parent. She put up posters — she calls them “gentle propaganda” — that touted the importance of immunization in stopping the spread of disease. Her husband helped create a spreadsheet to track which children at the school are missing which vaccinations.
Some parents have said that Haight’s provaccination message has no place at preschool, that it’s disrespectful and patronizing, that the decision to vaccinate a child is nobody else’s business. One mother got so emotional that she broke out in hives. But Haight thinks a conversation is critical, and the latest research published in the journal Pediatrics backs her up.
“I’m just trying to let people know that if you don’t vaccinate your children, it might affect other children’s health,” says Haight. “It directly affects a community of young children. How do we not talk about this?”
The problem to be overcome, however, is described in this study. As I read it, I was thinking that an anthropologist is the perfect person to look at the social groups that shape vaccination decisions. In this case, Brunson surveyed 126 parents who followed the nationally recommended childhood vaccination schedule from the CDC (referred to as “conformers,” which I really didn’t like) and 70 others who either delayed vaccination (28), partially vaccinated (37), or didn’t vaccinate at all (5) (all of them referred to as “noncomformers,” which I also didn’t like). 95% of both groups reported consulting their “people network” for advice and insight into vaccination decisions, and around 90% of each group included a physician in the top five members of their decision-making network. However, as you might expect, what those “people networks” told them was very different. Basically, 73% of “nonconformers’” friends and relatives advised them to disregard the CDC vaccination schedule, while only 13% of “conformers’” friends and relatives advised them similarly.
Now here’s why this is so important. The significance of what the conformers’ and nonconformers’ friends and relatives far outstripped any other factor studied. It “blew any other variable out of the water,” as Dr. Brunson put it, or, as she put it in her paper:
This is important to note because of all of the variables consideredin this study, the percent of network members recommending nonconformity was the most important in terms of predicting parents’ vaccination decisions. Considered by itself, this variable was more predictive of parents’ vaccination decisions than any demographic or general characteristic of parents or their networks. It was also more predictive than the percent of parents’ source networks recommending nonconformity and even parents’ own perceptions of vaccination. This strongly implies that for interventions aimed at promoting vaccine acceptance to be successful, they must take a broad approach, one that is capable of influencing not only parents but the people parents might discuss their vaccination decisions with. In other words, interventions targeted only at parents or interventions aimed primarily at improving communication between parents and their children’s health care providers will likely be inadequate because they fail to consider the broader impact of parents’ people networks.
The end result was that parents whose networks mostly recommended not follwing CDC immunization guidelines were more than 1,500 times more likely not to adhere to the CDC vaccination schedule compared to other parents. Even having between 26% and 50% of people in their social networks resulted in parents who were 31 times more likely not to vaccinated as recommended. In other words, it matters with whom young parents associate. It matters what their social networks believe. It matters a lot. Just look at King County, where there is a strong antivaccine sentiment to the point that what should be noncontroversial pro-vaccination messages result in strong pushback and one parent breaking out in hives because she’s so upset. In such a social network, even fairly pro-vaccine parents might start to change their minds. At least, it would take considerable fortitude for them to stand their ground.
Antivaccinationists know this. They know that the way to persuade parents not to vaccinated is to create social networks in which like-minded parents, friends, and relatives congregate and reinforce each others’ beliefs that vaccines are evil. That’s why they go so far to create such networks online. What is the “Thinking Moms’ Revolution” (or, as I like to call it—more accurately, I might add—The “un-Thinking Moms’ Revolution”) but a self-reinforcing echo chamber in which antivaccine moms tell each other how brilliant they are, how superior they are to the moms who vaccinate (the call themselves, without a trace of irony, “Thinkers”), and to encourage each other to greater heights of antivaccine lunacy and quackery.
Of course, this survey isn’t without its problems. Dr. Brunson alludes to a central question about her results in an interview, in which she points out that this is a “chicken-and-egg” issue:
Experts said it’s not certain that the advice actually steered parents in an anti-vaccine direction: Parents who were already prone to shunning vaccines may have turned to like-minded people for reinforcement.
“It’s the chicken-and-egg question,” said researcher Emily Brunson, an assistant professor of anthropology at Texas State University, in San Marcos. “The answer is, we don’t know which came first.”
I rather suspect that there is a lot of truth to this, although I also rather suspect that anyone who is on the fence can be highly influenced by antivaccine parents and relatives. Again, antivaccinationists know this. They also know that parents who are vaccine-averse need seemingly reputable sources of information to to help them justify their decision. Indeed, in this study, parents who didn’t follow CDC guidelines were more likely to have extensive “source networks” that included books, blogs, websites, and magazine articles to which they turned for vaccine-realted information. Not surprisingly, 59% of these sources recommend ignoring CDC guidelines and promote the scientifically discredited notion that vaccines cause autism.
In a way, the results of this study are a bit of a “Well, duh!” result. At least, it’s a “Well, duh!” result that social networks would be important in influencing the decisions of new parents to follow the CDC vaccination schedule. What is a bit surprising is how strong the effect was in this model. Moreover, from a practical standpoint, it doesn’t much matter whether the reason for this result is that antivaccine-sympathetic social networks can change parents’ minds or that anti-vaccine-leaning parents seek out anti-vaccine leaning social networks for reinforcement of their decisions. The point is that it’s much, much harder to influence parents by just trying to influence parents. The message has to go beyond that and reach everyone. It’s not enough to concentrate just on parents. It’s not enough to concentrate on pediatricians. The approach has to be broad-based and comprehensive, because prevailing beliefs in social networks can trump all those sophisticated campaigns to promote the benefits of vaccination.
Places like King County show what can happen when the prevailing culture becomes too permeated with antivaccine beliefs.