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Failure to vaccinate increases risk to others as much as drunk driving

September 15th, 2021, 9:47pm by Sam Wang


Today in the Washington Post, I join columnist Leana Wen in considering vaccination’s consequences (and here is a PDF) – for other people. We argue that from the point of view of endangering other people, going unvaccinated is on a par with drunk driving.

Because of deadline pressure, there were several calculations that didn’t make it into the piece.

The relative risk to others of going unvaccinated is remarkably similar to that of drunk driving. Some critics of vaccine requirements have compared going unvaccinated to secondhand smoke – an annoyance to others, but not a major threat. This is categorically false.

As I wrote in 2015, the risk ratio is a measure we can apply to a wide variety of factors. For example, in the original finding in 1954 that smoking causes cancer, smoking a pack a day is linked with a 25-fold increase in the rate of lung cancer. That’s a risk ratio of 25. Secondhand smoke has a much lower risk ratio, 1.3. As annoying as it is to be stuck near a smoker, the exposure has a fairly small effect on your cancer risk.

A larger risk is that of drunk driving. Driving while under the influence of alcohol is linked with a 15-fold increase in the likelihood of getting into a car accident. Drunk driving is a notable danger to the innocent: three out of 8 drunk-driving fatalities are not the drunk, but instead other drivers and passengers.

Measured in terms of increased risk, failure to take the coronavirus vaccine is equally dangerous. Recent evidence from the Centers for Disease Control shows that unvaccinated people over the age of 18 are 5-fold more likely to get infected than those who are vaccinated. Another study in the New England Journal of Medicine shows that unvaccinated people test positive for almost 9 days on average, 3 times as long as vaccinated people. The combination of increased risk and longer infection means that a randomly chosen unvaccinated person presents 5*3=15 times as much risk to others as a vaccinated person.

The absolute risk of transmitting coronavirus is also high. In the last 7 days there are 1.065 M reported cases, a rate of 1 out of 308 people. Among those over 18, 65% are fully vaccinated. A little algebra leads to the conclusion that 1 out of 151 unvaccinated people are infected. At this moment, each infected person transmits the virus to 0.9 persons on average, which means that this week, 1 out of 168 unvaccinated people is sick and will soon infect another person. That is almost 4 times as high as the risk of an accident during one trip while drunk driving, 1 out of 625.

Quantitative evidence like this shows why until this year, mandatory vaccination was considered uncontroversial. Vaccines are a triumph of science – and of American society. I will close with a reminder from 2015, when the conservative writer Ben Domenech wrote:

We’ve had mandatory vaccines for schoolchildren in America since before the Emancipation Proclamation. The Supreme Court has upheld that practice as constitutional for over a century, and only the political fringes believe there ought to be a debate about such matters. This is one of the few areas where government necessarily exercises power.

Sources for graphic: NEJM Washington Post Journal of Automotive Safety CDC

Tags: Health

6 Comments so far ↓

  • 538_Refugee

    Do you think that Republican governors are secretly relieved at Biden’s actions on vaccine requirements? It’s saving their voters. ;) https://www.snopes.com/fact-check/neil-degrasse-tyson-vax-tweet/ Not that they ever seem to need a majority. :(

    They are claiming it’s a states’ rights issue during a global pandemic? If he did nothing they would be bemoaning his lack of leadership.

    • Sam Wang

      I think that when someone shows who they are, you should believe them.

      To me the question is why there is such a polarized conflict between some governors (not all; see Ohio and Massachusetts) and the President. It is remarkable to see a pandemic drawn into that conflict. We found it useful to stick with a public-health perspective using data and risk assessments.

  • John Hennessey

    Ben Domenech six days before this article was published:
    “I don’t see how anyone can honestly read my 2015 pro-vaccine argument – beliefs which I still hold – and see them as equivalent to what Biden is attempting here, which I expect courts to rebuff.”

  • ArcticStones

    What a powerful comparison!

    To me it is stunning how the USA has lost its lead in vaccinations.

    By comparison, in Norway (which started very late), 86.5% of adults are fully vaccinated and 91.2% have had at least one jab.

    Interestingly, Norway has achieved that without any vaccination mandates. Why? Because what we might call the “social contract” is still alive and well.

    Here, in certain states and amongst certain political demographics, it seems antivaxxers are essentially insisting: “But my part of the Community Pool is the Peeing Section!”

  • Weave314

    Isn’t this saying that the 15x risk is just the risk of transmission, not the risk of death or even serious illness? It makes it less comparable to the drunk driving stat, if so.

    I’m not saying that anyone has the right to decide to transmit a disease when a vaccine is available. And Covid is unpredictable and capricious. It looks like any infection can cause long term damage. But the stats seem to be comparing different things in the levels of risk.

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