COVID-19 vaccines pose only trivial risk of blood clots (or venous thromboembolism), according to a new study.

The findings run counter to claims from anti-vaccine proponents.

In addition, the study also found that becoming infected with COVID-19 poses a significant risk of venous thromboembolism (VTE).

“This population-based study found only atrivial risk for VTEfollowing COVID-19 vaccination,” says Peter L. Elkin, professor and chair of the biomedical informatics department in the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo.

“Given the large risk of VTE from COVID-19 infection, the risk-benefit ratio strongly favored vaccination,” says Elkin, first author of the study published in theJournal of Clinical and Translational Science.

The researchers launched the study in order to investigate whether or not receiving a COVID-19 vaccine put one at higher risk for developing VTE, a claim that had circulated widely on social media and in mainstream media.

“There was concern by some that COVID-19 vaccination might cause undue harm and VTE was one of the mechanisms implicated byanti-vaxxers,” Elkin says. “We wanted to know the truth.”

The study period ran from January 1, 2020 (just prior to the detection in the US of COVID-19) until March 6, 2022, and was based on data from veterans aged 45 years and older from the Department of Veterans Affairs National Surveillance Tool.

The data included 855,686 people who had received at least one dose of a SARS-CoV-2 vaccine and an unvaccinated control group of 321,676 people.

To clearly identify whether the vaccines might affect risk for VTE, the researchers accounted for many factors that are predictors for VTE, including age, race, sex, body mass index, and others.

The study found that vaccinated individuals had a VTE rate of 1.3755 per 1,000 people, which is 0.1% over the baseline VTE rate of 1.3741 per 1,000 in unvaccinated people.

“The excess risk was about 1.4 cases per million patients vaccinated,” says Elkin. “Given the fact that the rate of VTE with COVID-19 is several orders of magnitude greater than the trivial risk from vaccination, our study reinforces the safety and importance of staying current with COVID 19 vaccinations.”

Read the full article about COVID vaccines by Ellen Goldbaum at Futurity.