Cases of myocarditis of COVID-19 vaccine are rare and typically mild. You are more likely to experience myocarditis if you have COVID-19.
Rare cases of myocarditis have been reported after COVID-19 vaccination among young adults, but most who received medical care responded well to medications and rest. In fact, the risk of myocarditis was higher among those who had caught COVID-19.
According to the Centers for Disease Control and Prevention, "Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart."
According to a study published in the New England Journal of Medicine, cases of myocarditis remain rare in vaccinated individuals: There were an additional 2.7 cases of myocarditis for every 100,000 people in the vaccinated group compared with the unvaccinated group. However, SARS-CoV-2 infection is in itself a very strong risk factor for myocarditis: There were an extra 11 cases of the disease for every 100,000 people with COVID-19, compared with those who were uninfected.
Speaking on the matter, Dr. Brian Feingold, an expert on heart inflammation in children at the UPMC Children's Hospital of Pittsburgh, said to the New York Times that the "risks related to COVID-19 are higher than the risks related to the vaccine."
In August, Johns Hopkins Medicine stated that, since April 2021, there were over 1,000 cases of myocarditis and pericarditis in young adults and males in the U.S. However, most of these cases were mild, and patients improved quickly.
Efficacy rates of COVID-19 vaccines range from 80 to 95 percent. Vaccinating children and adolescents decreases the chance that they will transmit the coronavirus. COVID-19 vaccines were developed using science that has been around for decades. The vaccines currently available have been through all the required stages of clinical trials. Also, extensive testing and monitoring have shown that these vaccines are safe and effective. The CDC has recommended that everyone aged 12 years and older get vaccinated for COVID-19.
UPDATE: Recently The Daily Mail and the Guardian reported on a study from the University of California stating that young men were at an increased risk of myocarditis after the vaccine. The study has not been peer-reviewed, and cases of post-vaccine myocarditis remain extremely rare.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19, including symptoms, prevention, and available treatment, please refer to the World Health Organization or your national healthcare authority.