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Jeff Cercone
By Jeff Cercone December 13, 2022

There’s no evidence linking COVID-19 vaccine to these athletes’ strokes, blood clots

If Your Time is short

  • NHL player Kris Letang in November suffered his second stroke, which his doctor said was caused by a tiny hole in his heart at birth.

  • NFL rookie Max Mitchell is out for the season with blood clots his father said were caused by a hereditary condition.

  • NFL player Henry Anderson missed two months on the field after suffering a stroke, but doctors could not determine its cause.

  • Tennessee college basketball player Tamari Key’s season ended because of blood clots in her lungs. Few details were released about her condition.

Blood clots and strokes can happen to anyone at any age. Throughout the COVID-19 pandemic, though, persistent claims have alleged that the vaccines meant to protect against the virus are causing healthy young people to fall ill, or die suddenly.

We’ve fact-checked such claims in the past, and recently examined the Stew Peters’ movie "Died Suddenly," which repeats many debunked conspiracies about the vaccine.

A recent social media claim suggested that the news of four young athletes recently suffering from strokes or blood clots is related to the vaccines.

A Dec. 10 Facebook post from an account named Died Suddenly/Unwanted Effect read, "This marks the ‘4th’ Major U.S. Athlete to announce BLOOD CLOTS or a STROKE in little over a WEEK."

It showed images of four prominent professional and college athletes and listed their health conditions.

But there is no evidence presented to link their conditions to vaccines. For two of the athletes, the issues were caused by other health issues. For the other two, although the cause is not clear, there was no public mention from either of them about COVID-19 vaccines playing a role.

The athletes

Kris Letang, 35, a Pittsburgh Penguins defenseman, was ruled out indefinitely after suffering a stroke, the team announced Nov. 30. But it was not caused by a COVID-19 vaccine.

Letang had also suffered a stroke previously in 2014, the team said. Doctors said that stroke was caused by a tiny hole in his heart at birth that never closed, a condition called patent foramen ovale, which can raise the risk of stroke because a clot can travel through the hole and to the brain.

After Letang returned to the ice 10 days after his second stroke, team physician Dr. Dharmesh Vyas told reporters why Letang was able to recover so quickly.

"Last time, we actually had to figure out why he had the stroke. We already know that now. The timeline, in terms of diagnostics, was much shorter. We're just confirming what we knew already," he said, according to CBS Sports.

Max Mitchell, 23, a New York Jets rookie offensive tackle, was placed on the nonfootball injury list on Dec. 7, ending his 2022 season. A day later, ESPN reported that Mitchell’s father, John Mitchell, said his son has a hereditary blood-clotting condition called Factor V Leiden. The athlete is expected to make a full recovery from blood clots in his calf and lung, his father said. 

Factor V Leiden can increase a person’s chance of developing abnormal blood clots, commonly in the legs or lungs, the Mayo Clinic said.

Henry Anderson, 31, a Carolina Panthers defensive end, returned to the football field Dec. 11 after being out since late October. Anderson revealed that he missed the time because he had a stroke.

Doctors were unable to determine the cause of the blood clot in his brain that triggered the stroke, he said. 

"Every test we ran came back negative,'' he said, according to ESPN. "It was just something where I just kind of got unlucky, honestly.''

The ESPN article did not mention COVID-19 vaccines as factoring in the stroke. Anderson didn’t talk about it in other interviews we found in which he discussed his health, either. We also found no information specific to Anderson’s vaccine status. The National Football League doesn’t mandate COVID-19 vaccines, but said in August that about 95% of players were vaccinated.  

Tamari Key, 21, a senior college basketball player at the University of Tennessee, will miss the rest of the season due to blood clots in her lungs, the team said Dec. 8.

It’s unclear what may have caused the clots. Key made no mention of the cause of her clots or COVID-19 vaccines in a Dec. 8 Instagram post thanking fans for their support. Her COVID-19 vaccine status isn’t publicly clear. The school does not currently require students to be vaccinated.

A team spokesperson said Dec. 13 that he had no new information to share about Key’s health beyond Key’s Instagram post and coach Kellie Harper’s initial statement.

"My sole concern right now is that Tamari continues to get the medical care and guidance she needs and begins the gradual process of healing and returning to full strength. This is much bigger than basketball," Harper said Dec. 8. "We are so grateful that this medical condition was caught. Our entire program will be right beside Tamari during this process and welcomes prayers and positive thoughts from Lady Vol Nation and beyond."

About blood clots

Blood clots are fairly common and affect about 900,000 people yearly, the Centers for Disease Control and Prevention said. They can happen to anyone, of any age, and can cause serious injury or death. There are many risk factors, including injuries, slow blood flow, pregnancy, cancer and many more.

There is a small risk of thrombosis with thrombocytopenia syndrome (TTS) from the Johnson & Johnson COVID-19 vaccine, according to the CDC. The rare blood clotting condition occurred in approximately four cases per 1 million doses, the CDC said. 

The more widely used Pfizer and Moderna vaccines have not been linked to an increased risk of blood clots. However, studies show an increased risk of clotting after contracting the COVID-19 virus, according to the American Heart Association.

Another recent study from Cedars-Sinai shows that COVID-19 vaccines do not increase the risk of a stroke, but the virus itself does.

Our ruling

An Instagram post suggested strokes and blood clots recently reported in four young athletes are related to COVID-19 vaccines.

But two of the athletes were suffering from other conditions that caused their health issues. One said tests to determine his stroke’s cause were inconclusive. A college student had blood clots in her lungs, but there were no other public details available about her condition or vaccine status.

Meanwhile, there’s no evidence linking the Pfizer or Moderna vaccines to an increased risk of blood clots, though there is a small risk associated with the Johnson & Johnson vaccine. Experts said studies show that the COVID-19 virus can increase someone’s risk of blood clots.

We rate the claim False.

RELATED: 'Died Suddenly' repeats debunked COVID-19 vaccine claims, promotes conspiracy theory

RELATED: No clear evidence that COVID vaccines are responsible for strange blood clots observed by embalmers

RELATED: No, COVID-19 vaccines aren’t responsible for an increase in deaths

Our Sources

Facebook post, Dec. 10, 2022

ESPN, "Panthers' Henry Anderson had stroke in Oct., now ready to play," Dec. 7, 2022

Sheena Quick, FOX Sports Radio1340, tweet, Dec. 7 2022 

Carolina Blitz tweet, Dec. 7, 2022

ESPN, "Jets OT Max Mitchell dealing with blood clots, says father," Dec. 8, 2022

Mayo Clinic, "Factor V Leiden

Tamari Key, Instagram post, Dec. 8, 2022

Knoxville News Sentinel, "Lady Vols basketball center Tamari Key out for season due to blood clots in lungs," Dec. 8, 2022

CBS Sports, "Penguins' Kris Letang returns to practice less than two weeks after suffering stroke," Dec. 8, 2022

CBS Sports, "Kris Letang injury: Penguins star suffers stroke, will be out indefinitely," Nov. 30, 2022

Trib Live, "Hole in heart could explain Penguins defenseman Letang's stroke," Feb. 7, 2014

Mayo Clinic, "Patent foramen ovale," accessed Dec. 12, 2022

Centers for Disease Control and Prevention, "​​Venous Thromboembolism (Blood Clots)," accessed Dec. 12, 2022

Centers for Disease Control and Prevention, "What is Venous Thromboembolism?," accessed Dec. 12, 2022

American Heart Association, "Blood clot risk remains elevated nearly a year after COVID-19," Sept, 19, 2022

Cedar Sinai, "New Data Show COVID-19 Vaccine Does Not Raise Stroke Risk," Aug. 24, 2022

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There’s no evidence linking COVID-19 vaccine to these athletes’ strokes, blood clots

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