The US Food and Drug Administration added a warning to the literature that comes with Pfizer Inc/BioNTech and Moderna COVID vaccine shots on Friday, indicating the rare risk of heart inflammation after use. The fact sheets for health care providers for each vaccine have been revised to include a warning that reports of adverse events suggest increased risks of myocarditis and pericarditis, particularly after the second dose and with symptoms onset within a few days of vaccination, according to the FDA.
Out of approximately 300 million mRNA vaccine doses administered, more than 1,200 cases of myocarditis or pericarditis had been reported to the Vaccine Adverse Event Reporting System (VAERS) as of June 11. Cases appear to be significantly higher in males and in the week following the second vaccine dose. The CDC reported 309 hospitalizations for heart inflammation in people under the age of 30, 295 of which were discharged. Several countries’ health regulators have been looking into cases of myocarditis and pericarditis, which are more common in young men, following a shot of Pfizer or Moderna, vaccines based on mRNA technology.
The latest FDA update comes after an extensive review of information and a meeting of the CDC’s Advisory Committee on Immunization Practices on Wednesday. After business hours, Pfizer and Moderna did not respond to requests for comment.