A large US-based study of tens of thousands of veterans concluded that the risk of developing blood clots as a result of the COVID-19 vaccine is negligible.
While this result may do little to convince many anti-vaccine advocates about the relative safety of vaccination, it is the community perception that vaccines are far safer than the diseases they seek to prevent. We hope to strengthen your trust. Venous thromboembolism (VTE).
“In this population-based study, we found that the risk of VTE after COVID-19 vaccination is negligible.” To tell Peter L. Elkin, MD, lead author of this paper and professor and chair of the Department of Biomedical Informatics at the University of Buffalo.
“Given the large risk of VTE from COVID-19 infection, the risk-benefit ratio strongly favored vaccination,” said Elkin. To tell.
This has long been the general consensus among experts, and fortunately, with 9.23 billion doses of the COVID-19 vaccine administered worldwide to date, it has resonated with much of the world. I’m in.
Clearly negligible does not mean zero risk. But if you’re unvaccinated and infected with SARS-CoV-2, your chances of developing a blood clot are orders of magnitude higher. The results are much higher in unimmunized populations with minimal safety measures.
Vaccines are widely credited for slowing the ongoing COVID-19 pandemic and saving countless lives in the process, and there is abundant evidence of their safety and efficacy.
But they have attracted suspicion from anti-vaccine advocates, many of whom point to news emerging in 2021 about a possible link between the COVID-19 vaccine and blood clots.
Despite scant evidence of a significant risk from vaccines, the concern persists, and its prevalence on social media and other public forums suggests that greater clarity could help.
“There was concern that COVID-19 vaccination could cause undue harm, and VTE was one of the mechanisms by which anti-vacciners were involved,” said Elkin. To tell“We wanted to know the truth.”
To do so, Elkin and his colleagues examined data from 855,686 US military veterans aged at least 45 who had received at least one SARS-CoV-2 vaccine at least 60 days earlier.
The control group included 321,676 individuals, also all US veterans of the same age group, who had not yet been vaccinated.
This data was obtained from the U.S. Department of Veterans Affairs’ National Surveillance Tool for the period from January 1, 2020 (just prior to the first known case of COVID-19 in the United States) to March 6, 2022. was covering
The researchers considered a variety of known VTE risk factors, including age, race, gender, and body mass index, to help focus attention on vaccine impact.
The VTE rate in vaccinated subjects was found to be 1.3755 per 1,000, which was 0.1% higher than the baseline VTE rate of 1.3741 per 1,000 in unvaccinated people.
“The excess risk was about 1.4 cases per million vaccinated patients,” Elkin said. To tell“Given the fact that the incidence of VTE due to COVID-19 is several orders of magnitude greater than the trivial risk from vaccination, our study supports the safety of staying up to date with COVID-19 vaccination. and reinforces its importance.”
A slightly higher risk may result from vaccine-induced immune thrombotic thrombocytopenia (VITT), and researchers believe that an immune response that alters platelet quantity and quality can lead to VTE. pointing out that
“VITT is now recognized as a rare complication of adenoviral vector-based SARS-CoV-2 vaccines,” they wrote, including Janssen’s (Johnson & Johnson) and AstraZeneca’s COVID-19 vaccines. I am referring to categories.
The study suggests that this modest increase in risk applies to both adenoviral vector vaccines and mRNA vaccines, including those manufactured by Moderna and Pfizer. “It’s not enough,” researchers argue.
On the other hand, there is no risk of VTE from actual COVID-19 infection.
VTE is a prominent consequence of COVID-19, occurring in about 8% of hospitalized patients and 23% of ICU patients, researchers note.
Based on 28 days of data on June 21, 2021, these figures show that of the 257,125 new COVID-19 cases recorded during this period, at least 3,203 COVID-19-related excess VTE cases occurred. suggests that However, if all these people were vaccinated, the expected number of excess VTE cases would be less than 1 (0.36).
“This study demonstrates the power of big data. Electronic health record data can be used in a rigorous way to answer questions that could not be adequately answered by randomized controlled trials. This is because of the small effect sizes and the need to recruit millions of people. To tell.
“This is an example of how biomedical informatics is answering important clinical questions,” he says. add“Help people recognize the benefits of COVID-19 vaccination and improve adherence to this approved clinical guideline.”
This research Journal of Clinical and Translational Science.
