Skip to content

Tuesday, Apr 20, 2021

Is blood clotting more likely from contracting COVID-19 than getting a COVID-19 vaccine?

Stevie Rosignol-Cortez, Gigafact Foundry
yes

Oxford University researchers compared incidence of a rare clotting condition—known as CVT, or cerebral venous thrombosis—among people suffering from COVID-19 and other groups. The disease itself places people at far greater clotting-related risks than do any of the three vaccines studied.

CVT occurred at a rate of 39 per million among COVID-19 patients.CVT occurred at a rate of about 5 in a million among recipients of the AstraZeneca vaccine.CVT occurred at a rate of about 4 per million among recipients of a first dose of an mRNA COVID-19 vaccine (the type offered by Pfizer or Moderna).

Data continues to accumulate as more vaccines are given.

Six cases of another type of CVT clotting, cerebral venous sinus thrombosis, were reported among 6.8 million U.S. recipients of the Johnson & Johnson vaccine. U.S. authorities have paused administration of that vaccine pending further reviews.

This fact brief is responsive to conversations such as this one.

Sources

About fact briefs

Fact briefs are bite-sized, well-sourced explanations that offer clear "yes" or "no" answers to questions, confusions, and unsupported claims circulating online. They rely on publicly available data and documents, often from the original source. Fact briefs are written and published by newsrooms in the Gigafact network.

See all fact briefs

Between 2020 and 2022, under close editorial supervision, Gigafact contracted a group of freelance writers and editors to test the concepts for fact briefs and provide inputs to our software development process. We call this effort Gigafact Foundry. Over the course of these two years, Gigafact Foundry writers published over 1500 fact briefs in response to claims they found online. Their important work forms the basis of Gigafact formats and editorial guidelines, and is available to the public on Gigafact.org. Readers should be aware that while there is still a lot of relevant information to be found, not all fact briefs produced by Gigafact Foundry reflect Gigafact's current methods and standards for fact briefs. If you come across any that you feel are out of date and need to be looked at with fresh eyes, don't hesitate to contact us at support@gigafact.org.

Learn More

Latest Fact Briefs

Be a Friend of facts

Help us fund more great fact briefs like this one.