Cases of myocarditis, or inflammation of the heart, have been reported after receipt of the COVID-19 mRNA vaccine.
Myocarditis following vaccination is short-lived and tends to resolve on its own, whereas myocarditis following an infection tends to be more severe.
The condition is continuing to be investigated. Here is what we know to date:
- The risk of myocarditis from COVID-19 infection appears to be greater than the risk of myocarditis from COVID-19 vaccination.
- The cases of myocarditis that have occurred so far were more often in boys and young men and more often after the second dose. Symptoms occurred within several days after receipt of the dose. Recently immunized teens and young adults who experience chest pain or shortness of breath should be seen by a health care provider and report their recent vaccination.
- Myocarditis is somewhat common, particularly as a result of viral infections. In fact, cases tend to occur more often in the spring due to viruses that circulate at this time of year (specifically, coxsackie B viruses). Typically, about 100-200 cases occur per million people per year.
- To date, about 530 million doses of the COVID-19 vaccines have been given, and about 16.6 million of these have been in teens (12 through 17 years old).
- Available data suggest that the incidence of myocarditis following mRNA vaccines is about 1 per 50,000 vaccine recipients. Of interest, myocarditis also occurs more commonly after either acute COVID-19 or as part of the multisystem inflammatory syndrome of children (MIS-C).
- Watch for symptoms that may include chest pain, pressure, heart palpitations, difficulty breathing after exercise or lying down, or excessive sweating. One or more of these symptoms may also be accompanied by tiredness, stomach pain, dizziness, fainting, unexplained swelling, or coughing. If a recently vaccinated teen develops these symptoms or you are unsure, contact the child’s doctor or seek more immediate medical assistance if needed.
The CDC will continue to monitor the situation related to myocarditis, but for now, there is not a reason to stop vaccinating kids. The American Heart Association has also released a statement encouraging continued vaccination.