US FDA adds warning about rare heart inflammation to Pfizer, Moderna COVID vaccines

The US drug regulator on Friday added a warning to the literature that accompanies Pfizer Inc /BioNTech and Moderna vaccine shots to indicate the rare risk of heart inflammation after its use.

For each vaccine, the fact sheets have been revised to include a warning about myocarditis and pericarditis, FDA said.

The latest update follows an extensive review of information and the discussion by CDC's Advisory Committee on Immunization Practices meeting on Wednesday.

Health regulators in several countries have been investigating whether the Pfizer/BioNTech and Moderna shots using new mRNA technology present a risk and, if so, how serious.

The CDC said that patients with heart inflammation following vaccination generally recover from the symptoms and do well.

The US Department of Health And Human Services, joined by leading US doctors groups and public health officials, put out a statement underscoring that the vaccines are safe and effective and that the heart side effect is "extremely rare."