Vaccine Avoidance and The Trolley Problem

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.


About Christine

I'm a full-time mother to two kids, an ex-lawyer, a breastfeeding counselor, a skeptic, and (to steal a phase from Penn & Teller) a "science cheerleader." You can reach me through my Facebook page.

Posted on November 22, 2011, in Health, Parenting, Skepticism and tagged , . Bookmark the permalink. 3 Comments.

  1. Hi Christine. There is one correction that I think needs to be made in your post. No vaccine that I know of (or that I or my daughter ever received) is injected right into a vein. Vaccines are injected into muscle. I’ve never even seen animals given intravenous vaccines and I used to give them myself while working for veterinarians.

    Additionally, the allergic reactions that are possible are usually seen right after an injection and if a child has not had a reaction to one vaccine, the chances are excellent that other vaccines will not cause reactions either. I think your idea of putting the actual probabilities on the vaccine inserts or information sheets is a good one, but it could be confusing to some people. I have found those sheets are pretty clear about the risks of disease and of reactions to be pretty clear. We just got our flu vaccines and the sheet was helpful. Find them at the CDC here:

    I can’t believe that there are mothers that will deny their children protection against a disease. I can’t believe that there are mothers that would purposely expose their children to chickenpox or other diseases when vaccines are much safer. The pseudoscience behind the anti-vax movement is incredible. In my opinion, not vaccinating without a valid medical reason should be considered child abuse and legally treated as such. By the way, I think many children that will remember that case of chickenpox they got as a child would be furious with their parents who failed to prevent the disease once a vaccine was available. (I just use chickenpox because it’s one of the vaccines many parents seem to think is “optional”.)

    It is sad when people have vaccine reactions (extremely rarely), but right now I feel it is most important for skeptics and the science community to oppose the anti-vax (or the “safe and sane vax”) pseudoscience that’s out there. All of our children are put at risk when people look at the vaccine non-issues illogically. As the CDC states on their information sheets “the safety of vaccines is always being monitored”.

  2. Lynn, you are absolutely correct, and I’ve fixed those references – thanks! When I think about it, I knew that, but damn it, “directly into the muscle” is nowhere near as poetic as “directly into the veins.” But accuracy trumps emotional impact.

    I do think a lot of moms are influenced by anti-vax pseudoscience, even if they don’t believe the autism bunk. And it’s a problem. But my question is how best to counter that, and I don’t think redrafting child abuse laws would be very helpful. In some cases it might be arguable that skipping a vaccine is neglect (if the child lived with someone with Hep B for instance), but I don’t like the idea of broadening the abuse and neglect definitions for this.

    For one thing, it will just make a lot of people drop medical care for their kids altogether, so no one can report them, or go to quacks who will certify that the kid has a condition precluding vaccination, or encourage people to finagle religious exemptions. For another, I don’t think it’s abuse or neglect. Every time you drive your kid around in a car you are endangering their health far more than you are if you skip the polio vaccine.

    Indeed a big part of the problem is a public health puzzle – since we’ve done such a brilliant job with vaccines, the likelihood that an individual child will encounter a VPD is very low. So people weigh the risks and decide it’s not worth vaccinating. But if enough individual children skip vaccination, the VPDs will become more common, and the risk of a kid getting it will be much higher. (See pertussis lately.) It’s kind The Tragedy of the Commons – each individual relies on the larger group to preserve something they “own” in common, but each individual wants to be the one person who can benefit without contributing. So the commons gets trashed and everyone suffers.

    I’ll probably do a post soon about how people view the herd immunity argument.

  3. (Hi there, just came across your blog.)
    I was somewhat bemused by your choice of the Amsterdam tram by way of illustration (I was born in Amsterdam, and my paternal grandparents lived there, so I’m well familiar with the model), though I guess “medical + trolley” doesn’t yield that many results. The tram in question (in the event you didn’t already know, or if you did, for the benefit of readers) has been refitted to transport physically handicapped people on tours of Amsterdam.

    I think you’re pretty much spot-on with your evaluation of parents’ thinking, but I think a factor that you perhaps missed is that a lot of people who are becoming parents now were themselves vaccinated during childhood and thus have no first-hand experience of them. My son was born when I was 35, I’m now 41, and I grew up in the Netherlands and the UK, where the MMR vaccine was not approved until the late 1980s. Well, at least I didn’t catch rubella. There’s nothing to dispel the question “well, how bad can an infectious disease really be?” like having actually had it, and I didn’t even suffer lasting damage. My son’s pediatrician says he wishes he could put me in a room with some of the vaccine-averse parents he gets in.

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