There have been reports of heart inflammation among young males. The CDC says such cases are rare and patients usually recover.
The CDC has written: "Since April 2021, there have been more than a thousand reports to the Vaccine Adverse Event Reporting System (VAERS) of cases of inflammation of the heart—called myocarditis and pericarditis—happening after mRNA COVID-19 vaccination (i.e., Pfizer-BioNTech, Moderna) in the United States."
The CDC added: "Patients can usually return to their normal daily activities after their symptoms improve."
The mRNA vaccines manufactured by Pfizer and Moderna are effective against COVID-19. The vaccines were approved by the FDA to be used for children aged above 12.
The CDC is investigating these heart inflammation reports.
According to CNN, "The US Food and Drug Administration added a warning about the risk of myocarditis and pericarditis to fact sheets for Moderna and Pfizer-BioNTech Covid-19 vaccines Friday."