After vaccination against Covid-19, heart muscle inflammation can occur in rare cases, especially in young men.

But how common is this side effect really?

A comprehensive study in "The Lancet - Respiratory Medicine" is now creating a new perspective: The research team from the National University of Singapore investigated whether myocarditis actually occurs more frequently after corona vaccination than after other vaccinations.

Johanna Kuroczik

Editor in the "Science" department of the Frankfurter Allgemeine Sunday newspaper.

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So far, an estimated ten billion doses of corona vaccine have been sprayed around the world.

The first comprehensive data indicating that inflammation of the heart muscle or pericardium is more common after mRNA vaccination against Covid-19 came from Israel.

In June 2021 it became known that young men were affected above average after the second dose of an mRNA vaccine.

Symptoms included severe exhaustion, shortness of breath or cardiac arrhythmia.

The heart muscle inflammation, which almost always heals, becomes visible through an imaging procedure.

The mechanism by which the vaccine could lead to a temporary inflammation of the heart is still unclear.

In any case, last summer the researchers assumed that there might be up to one case in 3,000 vaccinations.

In fact, the side effect is apparently much rarer.

In the current evaluation, the scientists come to around 18 cases per million corona vaccine doses.

To do this, they analyzed eleven research papers.

The risk was comparably high with other vaccinations, with 56 cases of myo- or pericarditis per million vaccine doses.

A total of 22 studies were included in the meta-analysis, which together included more than 400 million vaccinations - from studies in 1947 to New Year's Eve 2021. "Thus, the overall risk of myopericarditis with this new group of vaccines against Covid-19 does not appear to be different than conventional vaccines against other pathogens,"

Inflammation of the heart muscle after smallpox immunization occurred significantly more frequently than after the Covid 19 vaccination, with 132 cases per million vaccine doses.

After the flu vaccination, the number is comparable to the corona vaccines.

It is noteworthy, however, that after conventional vaccinations no major differences were found in the different age groups, heart muscle inflammation after Covid 19 vaccinations occurs more than average in young men, especially if they are under 30 years old and have had a second vaccination with an mRNA - had received a vaccine.

How often heart muscle inflammation normally occurs in the population - without vaccination - cannot be clearly determined.

The scientists from Singapore estimate that between 9.5 and 21.6 people per million develop myocarditis or pericarditis every month.

The illnesses are often mild, so that those affected do not see a doctor.

They can be the result of a delayed infection, for example if the flu or a severe cold is not healed properly and you then put yourself under physical strain.

It is therefore important to weigh the risks of vaccination against the risks of corona infection, the researchers summarize.

Because after an infection and Covid-19 disease, heart muscle inflammation also occurs in some cases - and this was significantly increased in previous studies, especially after a severe course.

In a recent study in Circulation of acute myocarditis in hospitalized patients of all ages, the disease occurred at 2.4 to 4 cases per 1,000 patients.

However, it is unclear how many remain undetected.

A consensus statement by the American Heart Association on experiences in pediatric medicine emphasizes that the risks of myocarditis and pericarditis continue to outweigh the benefits of vaccination and thus protection against Covid-19 disease.

4 to 4 cases per 1000 patients.

However, it is unclear how many remain undetected.

A consensus statement by the American Heart Association on experiences in pediatric medicine emphasizes that the risks of myocarditis and pericarditis continue to outweigh the benefits of vaccination and thus protection against Covid-19 disease.

4 to 4 cases per 1000 patients.

However, it is unclear how many remain undetected.

A consensus statement by the American Heart Association on experiences in pediatric medicine emphasizes that the risks of myocarditis and pericarditis continue to outweigh the benefits of vaccination and thus protection against Covid-19 disease.

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