Monday 3 October 2022 10:12 PM Up to one in 7,000 American teens suffered heart inflammation after their Covid ... trends now
Thousands of American teenagers may have suffered heart inflammation after getting a Covid jab, a study suggests.
Researchers found up to one in 7,000 boys aged 12 to 15 years old developed myocarditis after receiving the Pfizer vaccine.
The condition — which is mild for most but can cause a recurrent heart palpitation in rare cases — was most common after the second dose.
Covid is also mild for most teenagers with only 1,745 Americans under-18 dying from the disease compared to more than 800,000 over-50s.
Experts said their paper was not proof people should stop being vaccinated, adding the benefits still 'greatly outweigh' the risks.
Covid itself is known to cause myocarditis, with some studies known it is more common from infections than after an inoculation.
Vaccinating children has been hugely contentious during the pandemic because of the smaller risks Covid poses to them compared to older adults.
The above graph shows the risk of suffering myocarditis by doses, based on people under 40 years old and up to seven days after getting their jab. Risk was highest after the second dose
Researchers at the healthcare provider Kaiser Permanente reviewed 340 cases of myocarditis and pericarditis in hospitals across eight US states.
Myocarditis is when the heart muscle becomes inflamed, while pericarditis is when the lining of the heart becomes inflamed.
Overall, across all under-40s the rate of the side-effect was one in 30,000 after a second dose.
It was one in 200,000 after a first jab, and one in 50,000 after a booster dose.
Experts did not attempt to explain the difference between doses, although it may have something to do with the immune system responding for a second time.
Myocarditis is triggered when the body's immune system causes inflammation — often because it is battling an infection such as from Covid.
The findings were published today in the Annals of Internal Medicine.
For the paper, they monitored 6.9million Covid vaccine recipients for whether they visited an ER ward with myocarditis.
This included symptoms such as a fluttering heart or being short of breath within a week of being vaccinated.
All participants got their jabs between December 14, 2020 and May 31, 2022, across eight US states including California, Colorado and
