Heart inflammation after mRNA vaccinations

Since the end of April, we've known that cases of heart muscle inflammation (myocarditis) can also occur in young and athletic people  after COVID-19 vaccinations with mRNA vaccines. Health authorities in Israel were the first to report this. By that stage, they were already well advanced in their vaccination campaign and also had extensive patient data.

Now, the US Centers for Disease Control and Prevention (CDC) also report that there have been more than 1,000 cases of myocarditis and pericarditis (an inflammation of the outer lining of the heart) in the United States since April following mRNA vaccination against COVID-19. The CDC treat these cases as vaccine side effects. They occurred in people who had received vaccines from BioNTech/Pfizer and Moderna. The cases are very rare: About 13 in a million. 

Most of those affected were adolescents and young adults  over the age of 16. And the cases typically occurred within a few days of the second vaccination. The CDC statement said "most patients who received care responded well to treatment and rest and quickly felt better."

Inflammation usually follows infection

Inflammation of the heart muscle or pericardium does not just occur as a vaccination side effect. It can affect healthy and athletic people and, in some cases, can even be life-threatening.

This danger is particularly great if, for example, endurance athletes do not recognize an infection or do not take it seriously and continue to exercise when their bodies require rest.

The most common triggers  are viruses, especially cold viruses (adenoviruses and coxsackie viruses), herpes viruses or flu viruses. SARS-CoV-2 also frequently causes the two forms of cardiac inflammation. Usually, the inflammation is a result of the body's immune response to the virus.

Consequently, autoimmune diseases can also trigger such inflammation, as can drugs, environmental toxins such as heavy metals or radioactive substances, or injuries. Fungal infections also pose a risk, especially for people taking immunosuppressive drugs. 

What symptoms should I look out for?

After a vaccination, anyone who feels chest pain, is short of breath or feels that their heart or pulse is beating particularly fast, fluttering or pounding, should see a doctor. These symptoms are a warning signal, especially during the first week after vaccination.

Should I still have myself or my child vaccinated?

People are many times more likely to suffer a serious heart infection after a COVID-19 illness than after a COVID-19 vaccination. Moreover, in the cases reported from the US, the heart infections usually healed after the vaccinations.

In this respect, the CDC continue to recommend the COVID-19 vaccination for everyone 12 years of age and older. It's also important to get the second shot to have full vaccine protection, the agency says.

The German Standing Committee on Vaccination (StIKo) has not yet made a general recommendation for children and adolescents, even though the BioNTech/Pfizer vaccine has already been approved by the European Medicines Agency (EMA) for people 12 years and older. Parents are therefore free to have their children vaccinated after consulting their doctor.

In any case, parents of children or young adults with certain pre-existing conditions should speak to a doctor before vaccination.