by Adam Lee on February 16, 2023

This is an amazing study: anti-vaxxers get in more car crashes than vaccinated people.

The research team, from medical institutes in Toronto, used vaccination databases to identify Ontario residents who’d gotten a COVID vaccine. They used government records to enrich this data set with demographic information.

Then, over the following month, they queried 178 hospitals across Ontario to compile a list of patients who came to an emergency room because of injuries sustained in a traffic accident. This yielded a total of 6,682 people hurt or killed in car crashes.

They matched these data sets against each other, and here’s the result:

A total of 11,270,763 individuals were included, of whom 16% had not received a COVID vaccine and 84% had received a COVID vaccine. The cohort accounted for 6682 traffic crashes during follow-up. Unvaccinated individuals accounted for 1682 traffic crashes (25%), equal to a 72% increased relative risk compared with those vaccinated…

The increased traffic risks among unvaccinated individuals extended to diverse subgroups, was similar to the relative risk associated with sleep apnea, and was equal to a 48% increase after adjustment for age, sex, home location, socioeconomic status, and medical diagnoses[.]

“COVID Vaccine Hesitancy and Risk of a Traffic Crash.” Donald A. Redelmeier, Jonathan Wang, and Deva Thiruchelvam. The American Journal of Medicine, February 2023, vol. 136 no. 2.

This is a huge difference. It’s not some subtle pattern that can only be spotted by careful parsing of the data. As the researchers say, the increased risk associated with COVID vaccine refusal is comparable to sleep apnea. The only disorder that’s more predictive of crash risk is alcoholism.

There are some limitations on this study. It doesn’t include either accidents so minor that no one needed emergency care, or accidents so severe that the victim died at the scene. It also can’t differentiate between people who had legitimate medical or other reasons for not getting vaccinated, versus those who could have and just chose not to.

However, the impact of vaccine refusal remained after controlling for other confounding factors, like age, sex, income, and urban versus rural residence. Every subgroup with a significant number of crashes showed the same clear pattern.

What accounts for the correlation between these two seemingly unrelated outcomes?

Nonjudgmental

One possibility is that both COVID and car crashes are more likely to strike people who are bad at judging risk. This might be because they’re undereducated and lack critical thinking skills. It might be out of religious belief which makes them assume they enjoy divine protection. Or it might be because of a macho worldview that drives them to disregard danger in performative ways.

Whatever the cause, the result is the same. Some of these people don’t bother getting vaccinated against COVID because their calculation of risk is off. They assume they won’t catch the virus, or that it’s no worse than a cold. (Remember Phil Valentine?) Others swallow propaganda which leads them to believe, wrongly, that the vaccine is riskier than the disease.

The same faulty risk assessment could be at play in auto accidents. The people who believe they’re invulnerable to the virus might also speed, blow through stop signs, or swerve in and out of traffic because they believe nothing bad will happen. They’re led astray by the just-world delusion which assumes they’ll never fall victim to random chance.

Don’t tell me what to do

There’s a darker alternative: it could be that the causal link is an antisocial worldview.

It’s one thing to have bad judgment of the odds. However, that still assumes a rational risks-versus-benefits way of viewing the world. Some people reject this way of thinking altogether. They dislike being told what to do, and they dig in their heels against anything they perceive as coercive, even if it would improve their lives. The culture war over gas stoves is one example.

Vaccination falls squarely into this category. It’s a prosocial act: it both protects you and benefits society as a whole, by reducing the spread of the virus to vulnerable people. For most of us, that’s the definition of a win-win. But some people hate vaccine mandates so violently that they’ll refuse out of spite, regardless of the benefits.

This mindset isn’t confined to any one corner of the political spectrum, but it’s especially common among conservatives and libertarians. It might also bleed into traffic laws, treating them as impositions on individual freedom that should be resisted. (One example is Ron Smith, a motorcycle-riding Florida attorney who fought for the repeal of helmet laws. Guess how he died.)

How to reach the misinformed (or not)

Which of these explanations turns out to be true matters for a public-health outreach strategy. If people’s poor judgment of risk is the problem, rather than ideological resistance to vaccines, then it’s conceivable that we could fix it with better education and better messaging. Maybe we need “scared straight” ads, like the kind for tobacco, that show just how bad COVID can be.

But if an antisocial worldview is the cause, it’s a much harder problem. This kind of person will reject, on principle, anything that makes their life better. The more you try to convince them, the more stubborn they become. Trying to win them over is likely a lost cause. It may be that the most useful purpose this group can serve is if they become a cautionary tale for others.