The Inflated Risk of Vaccine-Induced Cardiac Arrest

Updated at 9:45 a.m. ET on January 5, 2023

During this week’s Monday Night Football game, the 24-year-old Buffalo Bills safety Damar Hamlin collapsed moments after making a routine defensive play. Hamlin seemed to have suffered a blow to his chest shortly before losing consciousness from cardiac arrest, and his condition is grave. The source of his illness remains unclear. A study of sudden cardiac events in U.S. athletes from 2014 to 2016 found that structural abnormalities of the heart muscle or arteries and faulty electric rhythms were the most common causes; traumatic chest injuries have also been linked to such incidents, in a rare condition called commotio cordis. Still, the availability of these hypotheses did not stop online activists from blaming Hamlin’s health crisis on vaccines.

Anti-vaccine influencers have been fomenting fear about a supposed rise in COVID-shot-induced athletic deaths for a while. Fact-checkers have repeatedly assessed these claims and found them to be without merit. Jonathan Drezner, a sports-medicine physician who studies sudden deaths in athletes, told media outlets last year that he was “not aware of any COVID-19 vaccine-related athletic death.” The National Center for Catastrophic Sport Injury Research, which systematically tracks sports-related fatalities, identified 13 medical deaths during football-related activities in 2021 among players participating at all levels of competition, eight of which were caused by cardiac arrest. The same researchers had found 14 medical deaths two years earlier, 10 of which were heart-related. These incidents remain tragic and scarce.

The mRNA shots by Pfizer and Moderna are associated with a very small risk of heart inflammation, called myocarditis, which can lead to cardiac arrest. This risk is most pronounced in teenage boys receiving a second dose of the vaccine, but even in that scenario only about one or two recipients out of every 10,000 are affected. (Most professional athletes are in their 20s, not teens, so the risk to them is lower.) Myocarditis is a potentially fatal condition, but the version that occurs after vaccination is much less deadly than the heart inflammation induced by many viruses, including SARS-CoV-2. A recent analysis identified only a single death in 104 cases of vaccine-induced myocarditis. In comparison, for every 100 people who get myocarditis from a virus, about 11 will die.

The mere fact that mRNA shots can lead to heart problems has been exploited by conservative commentators and politicians to exaggerate the risks to young people. Last month, per a news release, Florida Governor Ron DeSantis promised to look into “sudden deaths of individuals that received the COVID-19 vaccine,” and called for a grand jury to investigate alleged wrongdoing by the vaccine manufacturers. His petition to the Florida Supreme Court justified the investigation by pointing out that “excess mortality from heart attacks rose significantly during the COVID-19 pandemic, especially among individuals ages 25 to 44.” Yet the rise in youth heart attacks actually began in 2020, before vaccines were available. That’s because increased cardiac fatalities during the pandemic have mostly been due to the coronavirus itself. Heart-disease deaths in the United States have been observed to rise and fall in near lockstep with waves of COVID deaths, suggesting that most of these cases—97 percent, according to one estimate—are the result of undocumented SARS-CoV-2 infection.

DeSantis’s crusade against vaccines is backed by his surgeon general, Joseph Ladapo, who is a staunch opponent of inoculating young people against COVID. (He has encouraged the use of ineffective therapies such as hydroxychloroquine and ivermectin, though.) In October, Ladapo’s department produced an anonymous, non-peer-reviewed analysis suggesting that COVID shots were causing an increase in cardiac fatalities in young men. This report was modeled on a study by the U.K. government, which came to the opposite conclusion about vaccines but did find that COVID infection was associated with a sixfold increase in youth cardiac death. Given the lack of detail provided in the Florida study, it’s hard to know how to reconcile its contradictory result. This week, a group of University of Florida physicians and scientists released a report that strongly criticized the work’s methodology.

The COVID vaccines are among the most widely used medical interventions. More than 13 billion doses have been administered, at least 1 billion of which relied on mRNA technology. In analyzing this trove of real-world data, researchers have occasionally identified potential safety issues. A lack of perfect consistency across their studies is expected, and only confirms that the scientific dialogue about this new technology has been transparent. Scientists know that findings made outside a clinical trial are prone to spurious associations, so they examine how well each analysis has been performed and interpret it in the context of prior research.

Vaccine skeptics prefer to cherry-pick supportive studies while ignoring others that contradict them. Ladapo, for example, has cited a Scandinavian report showing a potential increase in post-vaccine blood clots and heart attacks. Yet the study authors themselves cautioned readers against relying too heavily on their results, because the finding was observed in only some age groups and time periods but not others. Ladapo also failed to mention that similar studies out of the U.K., France, Scotland, and elsewhere had not found a meaningful increase in blood clots or heart attacks with mRNA shots.

A careful recitation of facts can take one only so far in combatting anti-vaccine claims. Activists use ambiguous anecdotes such as Hamlin’s cardiac arrest and the sudden death of the soccer journalist Grant Wahl during last month’s World Cup to make the alleged risks of the shots more visceral. Sports are much less dangerous than SARS-CoV-2, but when unexpected tragedies do occur, they lead to an outpouring of mourning and reflection. Collective trauma can easily give way to collective speculation, and partisans on all sides will be happy to tell us what really happened. Yet convenient scapegoats will not be enough to mend our grief.

This article originally stated that the risk of myocarditis for teenage boys after a second dose of mRNA vaccine is about one in 10,000. In fact, it is about one or two in 10,000.

You may also like


How Worried Should We Be About XBB.1.5?

After months and months of SARS-CoV-2 subvariant soup, one ingredient has emerged in the United States with a flavor pungent

I’m Sorry, but This COVID Policy Is Ridiculous

Cases have surged in China since it dropped its zero-COVID policy in December, and the latest models now suggest that