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Long, fibrous blood clots have been found in the arteries of people vaccinated against COVID-19.

There is no link between long fibrous blood clots and the Covid-19 vaccine.


Swedish health misinformation site Newsvoice wrote an article about long fibrous blood clots found by Richard Hirschman, an American embalmer, implying that COVID-19 vaccines were the cause of the blood clots. An experiment was conducted by the far-right conspiracy theorist Mike Adams to test the blood clots with ICP-MS (Inductively Couples Plasma Mass Spectronomy). The blood clots were compared during the experiment with blood from an unvaccinated person. The experiment found that it lacked important elements from healthy human blood, such as iron, potassium, magnesium, and zinc, indicating that it was made from something other than blood. However, the claim is false. 

In fact

Although Hirschfield claims the clots were caused by COVID-19 vaccines, doctors and experts say that the clots are more likely to be caused by common chronic health problems, such as smoking, obesity, or other conditions, and have nothing to do with vaccination. 

The NewsVoice article was based on a September 2 article in the Epoch Times. Health Feedback, a fact-checking site that uses doctors to write about medical claims made in the media, debunked the claims. They found that there was no support for the COVID-19 vaccines to cause these sorts of clots. 

Instead, COVID-19 increased the risk for blood clots more than the vaccines. A Swedish study found that an increased risk of blood clots remained up to six months after being infected with the virus, which could explain why they were found post-mortem.

Health Feedback addresses the experiment cited by NewsVoice and The Epoch Times, which was based on Mike Adams's report on his website Natural News. Firstly, there was a lack of transparency as basic clinical information about the individuals from whom the samples were taken was absent. Furthermore, only one blood sample and one blood clot were tested, which is not representative of a broader population. 

Secondly, Adams' main claim was that there was insufficient iron in the blood clot, which makes it unnatural. Health feedback reports that the amount of iron present in a blood clot depends on where it was formed, such as a blood clot in an artery, vein, or lung. 

Thirdly, Adam states in his article that the laboratory routinely tested dog and cat food samples, but that human biological sample was not encompassed by the laboratories accreditation scope. Health Feedback says this undermines the reliability of Adams's result as the laboratory might not be properly equipped to test human samples accurately.

Similar claims surfaced in January 2022 which was published by the misinformation site NewsWars, run by the conspiracy theorist Alex Jones: "Embalmers finding 'Strangle clots' in Jabbed people." The claim that Covid vaccines were causing these blood clots was debunked by PolitiFact, as the blood clots had been found in unvaccinated deceased people before the vaccines were available.


There is no support for the connection between these blood clots and the COVID-19 vaccine. Furthermore, the methodology used by Mike Adams to study the blood clots and compare them to blood samples is severely lacking and unreliable, and based on outright misunderstandings of medicine. Most of the sources involved, including Mike Adams and the Epoch Times, have been known to promote misleading or false claims about COVID-19 vaccines. We mark this claim as false.

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