U.S. FDA adds heart risk warning to Pfizer, Moderna COVID vaccines

The U.S. drug regulator on Friday added a warning to the literature that accompanies Moderna and Pfizer-BioNTech COVID-19 vaccine shots, indicating the rare risk of heart inflammation after its use.

For each vaccine, the Fact Sheet for Healthcare Providers Administering Vaccine (Vaccination Providers) has been revised to include a warning about myocarditis and pericarditis, said the U.S. Food and Drug Administration in a new release.

The warning notes that reports of adverse events suggest increased risks of myocarditis and pericarditis, particularly following the second dose and with onset of symptoms within a few days after vaccination.