COVID-19 Vaccine Opponents Misrepresent CDC Webcast on Causes of Blood Clots


SciCheck Digest

The Centers for Disease Control and Prevention hosted an online seminar about the treatment of blood clots, which is expected to grow as the U.S. population ages and the obesity rate increases. But some vaccine opponents misrepresented the webinar to falsely suggest that the projected rise in blood clots is related to the COVID-19 vaccines.

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The Centers for Disease Control and Prevention hosted a webinar on Sept. 22 about the treatment and prevention of blood clots.

Health care providers expect the number of patients who are at risk for developing clots, and needing anticoagulant care, to grow significantly as the population ages and the obesity rate increases over the next few decades. More on that later.

The webcast featured Allison Burnett, president of the Anticoagulation Foruman organization that works with health care providers to improve patient care. It was moderated by Dr. Caroline Cromwell, the medical director of the thrombosis services program for the Mount Sinai Health System in New York.

Most of the attendees for the webcast — 73%, according to a user-generated poll — were health care providers. The archived YouTube version has garnered 89 views.

But then it got hijacked.

On the same day that the webcast was posted, Candace Owens, a conservative political commentator who has advocated against COVID-19 vaccines, posted a video on social media referencing the CDC’s synopsis of the seminar (shown in the tweet at the right), which said that the estimated number of patients needing anticoagulant care would double by 2050. Owens then baselessly suggested that this was related to the vaccines. The video received more than 31,000 likes on Instagram, alone.

Other anti-vaccine campaigners posted similar videos, including Canadian conspiracy theorist Chris Saccoccia, who goes by Chris Sky online.

A day after the webinar, Saccoccia posted a video on Telegram citing the same CDC synopsis, and said in part, “So, all you people that took your jab. All you people that are not very bright. All you people that are taking time off to die. Guess what happened today? The CDC just announced — in their infinite wisdom — that they expect the number of people to need anticoagulants — and for all you people that don’t understand what that means, but still took your vaccines because you’re geniuses, that is blood clot treatment, anticoagulants are for blood clots — so why is the CDC making the statement they expect the number of people to suffer from blood clots to double — double! — right after the jabs for the first time ever in human history?”

Like Owens’ followers, Saccoccia’s followers responded with variations of the misguided belief that COVID-19 vaccines were to blame. Saccoccia’s video has been viewed more than 24,000 times on Telegram and copied on Rumble.

But if any of them watched the webinar, instead of drawing a mistaken conclusion from a short synopsis posted by the CDC on Twitter, they would have learned that studies predating the COVID-19 vaccines by several years suggest there will be an increased need for anticoagulant care.

That’s because two of the most common medical conditions requiring anticoagulants are expected to increase as the population ages and obesity rises, Burnett explained to us in a phone interview. Those conditions are atrial fibrillation, or AFib, a type of irregular heartbeat that can cause clotting and becomes more common as people age, and venous thromboembolism, or VTE, which refers to blood clots that start in a vein. Risk factors for VTE include obesity, hospitalization and age.

Together, those two conditions are going to drive up the number of patients who are going to need anticoagulants, Burnett said.

That rise in anticoagulant care has nothing to do with COVID-19 vaccination, she said.

In fact, she said a person is much more likely to get a blood clot after being infected with COVID-19 than they are to get a clot after being vaccinated.

“So the message is — get vaccinated to avoid blood clots,” since getting infected can increase the risk of clots, Burnett said.

That message is backed up by a British study published on Sept. 19 in Circulation, an American Heart Association journal, which found that the incidence of clots “remains elevated up to 49 weeks after COVID-19 diagnosis.” The study concluded, “These results support policies to prevent severe COVID-19 by means of COVID-19 vaccines, early review after discharge, risk factor control, and use of secondary preventive agents in high-risk patients.”

It’s worth noting, as we’ve explained before, that one of the vaccines available in the U.S., made by Johnson & Johnson, can cause a particular kind of clotting that has been seen mostly in one group of people — women under 50. But the condition is very rare, and in December the CDC recommended the two mRNA vaccines over Johnson & Johnson’s. Only about 3% of the vaccine doses administered in the U.S. have been from Johnson & Johnson.

This is not the first time we’ve seen this kind of misrepresentation of remarks from the CDC.

In February, online posts misleadingly linked a CDC public health campaign on deep vein thrombosis to COVID-19 vaccines. But, as we explained, blood clotting in the deep veins is a relatively common medical condition. The CDC had simply tweeted out a link to its page on this serious condition in an effort to raise awareness. The tweet also had nothing to do with COVID-19 vaccines.

Editor’s note: SciCheck’s COVID-19/Vaccination Project is made possible by a grant from the Robert Wood Johnson Foundation. The foundation has no control over’s editorial decisions, and the views expressed in our articles do not necessarily reflect the views of the foundation. The goal of the project is to increase exposure to accurate information about COVID-19 and vaccines, while decreasing the impact of misinformation.


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