1 in 3 Americans believe COVID vaccines caused thousands of sudden deaths—here’s what the data show

A poll in 2023 revealed roughly one in three Americans believe that "COVID-19 vaccines have caused thousands of sudden deaths in otherwise healthy people" is probably or definitely true. This is one of the major rumors that spread fear of COVID vaccines, with some health departments now forbidden to promote COVID shots or even outright banning them.

The 'sudden death in athletes' rumor

The rumor of “thousands of deaths” was partly driven by viral videos of young, healthy athletes collapsing on the field, alleging COVID vaccines were to blame. But further investigation revealed these clips were highly misleading – for many of the clips either 1. the collapsing athletes hadn't received a COVID shot or 2. the death occurred well before COVID vaccines were even available. 

After the on-field cardiac arrest of Buffalo Bill's Damar Hamlin in 2023, another viral rumor launched claiming that athlete sudden deaths had increased dramatically in sports after the COVID vaccine rollout. But when you dug down into the details, the numbers were inaccurate and inflated – for example, some of the "athlete deaths" that were counted were not actually young, healthy athletes who died suddenly on the field, but instead were random news reports of people of all ages dying from many different causes, including an elderly woman who died at home.

A new study sheds some light

These rumors were based on news clips and blog posts, not robust analyses of athlete deaths across the country. A new study published in JAMA this week tested this hypothesis formally: was there any increase in sudden cardiac arrest (SCA, heart suddenly stops) or sudden cardiac death (SCD, heart suddenly stops leading to death) in young US athletes after either the introduction of COVID (2020) or COVID vaccines (2021)?

The answer is no. The highest year for both sudden cardiac arrest and death in the study was 2017, and overall the levels did not change much from year to year. There was no giant spike in deaths when the COVID vaccines rolled out in 2021. There was also no giant spike from COVID in 2020.

This is supported by other studies that have shown no increase in out-of-hospital cardiac arrest in young people (age 5-50) during the COVID vaccine rollout in Australia, and an overall decreasing rate of sudden cardiac deaths in NCAA athletes, a trend that continued during the COVID vaccine roll out in the US.

Not just one rumor

Athletes collapsing was not the only rumor that led people to believe COVID vaccines had killed thousands of people. There were many others that left one third of the country under the impression that COVID vaccines were deadly. A few others included:

• Misunderstanding blood clots: The viral video "Died Suddenly" alleged funeral embalmers had discovered dead vaccinated people were full of blood clots, failing to recognize it is normal for blood to clot after death. (If blood stops moving, as it does in death, it clots).
• Poor stats: Multiple analyses, including this one from Florida, alleged a link between COVID vaccines and cardiac death, but the stats didn't hold up.
• Post hoc fallacy: News stories of people who died after vaccination (without a clear link to the vaccine) and VAERS reports of deaths after vaccination (even if there was another clear cause) fed the rumor that any death after vaccination is a death caused by a vaccine, an error in reasoning known as the post hoc fallacy.

What about myocarditis?

There are real, rare risks from COVID vaccines, including myocarditis (inflammation of the heart). The risk is real but thankfully overall rare. It is higher for young men after mRNA vaccines, with 0.036% of males age 12-17 developing the condition after a second mRNA vaccine dose (in comparison, for this same age group this risk of myocarditis after COVID infection is about double that). While post-vaccine myocarditis is milder than other forms of myocarditis and most patients quickly recover, in rare cases there can be long-term complications.

The risk of myocarditis is real and should be taken into consideration when looking at the risks and benefits of vaccination. The problem is the impact of this risk has been profoundly exaggerated. Tragically, widespread rumors exaggerating harms from COVID vaccines has made it harder to talk about real side effects. Just last week, respected researchers posted a preliminary (not peer-reviewed) results about possible rare side effects from COVID vaccines, and the preprint exploded online leading to exaggerated claims. Often, those spreading these rumors say (and, I believe genuinely do) want increased vaccine safety – but ironically, their actions are making it harder, not easier, for scientists to study vaccine side effects and share their results, because they know the results will be taken wildly out of context.

Why do young athletes die suddenly?

So if COVID vaccines are not to blame for the sudden cardiac death in young athletes, what is? Often, undiagnosed heart conditions such as abnormalities in the structure or electrical system of the heart are the cause. This is a well known phenomenon in the medical world. These abnormalities can stay hidden for years, and then when the right conditions combine, the heart is pushed into a severe arrhythmia causing it to suddenly stop beating. These deaths are tragic, and the best way to prevent them is to learn CPR, not discourage vaccination.

Kristen Panthagani, MD, PhD, is a resident physician and Yale Emergency Scholar, completing a combined Emergency Medicine residency and research fellowship focusing on health literacy and communication. In her free time, she is the creator of the medical blog You Can Know Things and author of Your Local Epidemiologist’s section on Health (Mis)communication. You can subscribe to her website below or find her on Substack, Instagram, or Bluesky. Views expressed belong to KP, not her employer.