In a study from the University of Oxford, scientists found the overall risk of myocarditis – inflammation of the heart muscle – is substantially higher immediately after being infected with COVID-19 than it is in the weeks following vaccination for the coronavirus.
In the study, the team analyzed data from nearly 43 million people.
They found that across this large dataset, the entire COVID-19-vaccinated population of England during an important 12-month period of the pandemic when the COVID-19 vaccines first became available, the risk of heart inflammation following COVID-19 vaccination was quite small compared to the risk of heart inflammation after COVID-19 infection.
Myocarditis is the inflammation of the middle layer of the heart muscle wall, known as the myocardium. It is uncommon and typically triggered by a viral infection.
Myocarditis can weaken the heart muscle as well as the electrical system that keeps the heart pumping normally. The condition may resolve on its own or with treatment, or it may lead to lasting heart damage.
Previous research from around the world has shown a potential increased risk of myocarditis after receiving an mRNA COVID-19 vaccine.
The current analysis showed people infected with COVID-19 before receiving a vaccine were 11 times more at risk of developing myocarditis within 28 days of testing positive for the virus.
But that risk was cut in half if a person was infected after receiving at least one dose of a COVID-19 vaccine.
The risk for myocarditis increased after receiving the first dose of the AstraZeneca vaccine and after a first, second and booster dose of the Pfizer or Moderna vaccine.
But the risk of myocarditis associated with the vaccine was lower than the risk associated with COVID-19 infection before or after vaccination – with one exception.
Men under 40 who received a second dose of the Moderna vaccine had a higher risk of myocarditis following vaccination. The Pfizer and Moderna mRNA vaccines are available in the U.S.
The team says it is important for the public to understand that myocarditis is rare, and the risk of developing myocarditis after a COVID-19 vaccine is also rare.
This risk should be balanced against the benefits of the COVID-19 vaccines in preventing severe COVID-19 infection.
It is also crucial to understand who is at a higher risk for myocarditis and which vaccine type is associated with increased myocarditis risk.
If you care about Covid, please read studies about why are we seeing more COVID cases in fully vaccinated people, and this existing drug can save damaged lungs in COVID-19.
For more information about health, please see recent studies about a new drug that could prevent COVID-19, and results showing health care workers change their minds on COVID vaccinations.
The study was conducted by Martina Patone et al and published in Circulation.
Copyright © 2022 Knowridge Science Report. All rights reserved.
