The warning update was issued after extensive review and discussion of the information by the CDC Advisory Committee.

The U.S. Food and Drug Administration (FDA) has added warnings about the risk of heart inflammation in the fact sheets for Moderna and Pfizer-BioNTech COVID-19 vaccines.

Friday’s warning noted that reports of adverse events after vaccination-especially after the second dose-indicate an increased risk of myocarditis or inflammation of the myocardium, pericarditis, or inflammation of the tissues surrounding the heart.

The FDA said it updated the warning after an extensive review of the information and discussion at the Centers for Disease Control and Prevention (CDC) Immunization Practice Advisory Committee meeting on Wednesday.

At the end of the second week of June, the U.S. Vaccine Adverse Event Reporting System had reported more than 1,200 cases of myocarditis or pericarditis.

According to reports, the number of cases in men and one week after the second vaccination appears to be significantly higher.

Pfizer and Moderna have not yet commented on this.