We are talking about a rare side effect on the heart, WSJ notes.

The U.S. Food and Drug Administration have paused approving the Moderna coronavirus vaccine for adolescents to additionally test the drug for a rare side effect on the heart. The Wall Street Journal reported this on Friday.

According to her, the regulator wants to study more closely the possibility of myocarditis during vaccination of adolescents aged 12 to 17 years. To do this, they will compare the data on Moderna with a drug from the American company Pfizer and the German BioNTech.

According to the publication, the regulator has not yet established whether there is an increased risk of myocarditis after vaccination with the Moderna vaccine; it may take several weeks to check.

At the beginning of the month, medical regulators in Denmark, Sweden, and Finland suspended vaccination of young people with Moderna amid signals of possible side effects, such as myocarditis or pericarditis.

At the same time, Pfizer and BioNTech have already submitted an application to the FDA for approval of the emergency use of their coronavirus vaccine among children aged 5 to 11 years. Currently, the drug has a permit for use among people over 16 years old and for emergency use among adolescents from 12 to 15 years old.