Mention the vaccine debate to a skeptic, and their blood pressure will rise precipitously. Vaccine opponents like Jenny McCarthy leap to mind – people who are loud and aggressively irrational, who cling to discredited theories and practitioners and invoke tinfoil-hat level conspiracy theories to explain why the evidence is against them. It’s no wonder that vaccine supporters distrust and even revile anyone labeled as “anti-vax.”
But it’s not just a belief in Wakefield and his faked data about autism that motivates vaccine-cautious parents. Between those who adhere to the CDC schedule and those who hyperventilate about Congress forcibly turning children into “mercury-laced vaccinated guinea pigs” there are a lot of parents who are just worried about their kids’ health.
To be honest, I think a lot of their motivation originates in emotion rather than reason, but that doesn’t make them fringe loonies. They hear that a doctor wants to stick needles in their tiny, vulnerable baby and inject, well, stuff. Not only are they being injected with dead viruses and such, but there is some mystery about what else is floating in that syringe. Moms who scrupulously avoid pesticides, preservatives, dyes, and even sugar are told that the doc is going to deliver an industrially-produced cocktail of substances directly into their infants’ muscles. You have to admit, that’s kind of scary. And most people don’t emulate Mr. Spock and dispassionately weigh the relative risks of each decision. They are guided by their gut reactions. And in this case, their gut says, “that seems bad.” Humans aren’t really built to look at statistics and risk in a logical way – we react, then interpret evidence in light of that initial emotional reaction.
Humans are also really, really prone to the post hoc ergo propter hoc fallacy. Even if someone intellectually knows that one event closely following another doesn’t imply causation, the emotional impact of watching a child have a serious health problem shortly after a vaccination can’t be underestimated. And of course, some children really do have serious reactions that are related to vaccines. It’s quite natural and prudent for parents to withhold future vaccines from such children if there is an elevated risk of further reactions.
Generally, the reluctance about vaccinating on schedule is not due to parental neglect, but quite the opposite: parents who avoid vaccines tend to be extremely cautious about their children’s health. As alluded to above, many of the alternatively- or non-vaxing parents I know are exceedingly careful about birth interventions, breastfeeding, sleeping safety, car seat safety, nutrition, and every variable they can control in the slightest to maximize their children’s well-being.
Now, to some extent this caution may be misplaced. Parents may think that the risk of not vaccinating is lower than the risk of vaccinating. If vaccine inserts had a well-founded comparison chart that laid out the relative risk, maybe some of these parents would feel more comfortable vaccinating. The vaccine information statement I just got for the flu vax just states, “The risk of a vaccine causing serious harm, or death, is extremely small.” Well, the risk of my kid getting serious harm or dying of the flu is “extremely small” too, right? The statement goes on to warn that the vaccine could very rarely cause life-threatening allergic reactions. But veryvery cautious parents are going to read that and have serious harm . . . death . . . life-threatening jump out and stick in their memory, then compare that to the time they had the flu and felt a bit unwell for a week, and they will conclude that there is no way the risk is worth it. If the information statement had a table showing “Risk of death from vaccine = .000001” and “Risk of death from the flu = .000005” maybe people would have the data to make better decisions. (I totally and completely made up those numbers, just to demonstrate what I’m saying, by the way. I also realize that some may look at the research and conclude that the risk of death from a vaccine is actually higher than the risk from the disease. Personally I’d like some expert statisticians to analyze the data for parents.)
I also think that the vaccination decision is related to the ethical reasoning displayed in The Trolley Problem and its related hypothesis, The Fat Man. In those hypotheses, people are pretty willing to divert a train from a track that has five potential victims tied to it, even if that will accidentally cause the death of a single person. But people are generally reluctant to agree that they would push a fat man off an overpass to derail the train as it is about to hit five people. In both cases, the number of people saved compared to the number sacrificed is the same. But people are not willing to take deliberate action to harm someone, even in situations where they are willing to take an action they know will probably cause the same harm as an unintended consequence.
I think that parents who don’t vaccinate on the CDC schedule are functioning according to this pattern. They will risk their children happening to encounter a serious vaccine-preventable disease and being harmed. But they can’t accept the possibility that they might choose to inject shit right into their kid’s bodies and thereby cause them harm. That might not be a logical reaction. It might be frustrating to vaccine proponents and public health officials. But it is a profoundly human reaction.