More than 1,200 cases of heart inflammation in adolescents and young adults following Pfizer’s or Moderna’s COVID vaccine have been reported to health authorities in the United States, the Centers for Disease Control and Prevention (CDC) said on June 23.
The U.S. Food and Drug Administration said on Wednesday it plans to move quickly to add a warning about rare cases of heart inflammation in adolescents and young adults to fact sheets for the Pfizer/BioNTech (PFE.N), and Moderna (MRNA.O) COVID-19 vaccines.
U.S. Centers for Disease Control and Prevention (CDC) advisory groups, meeting to discuss reported cases of the heart condition after vaccination, found the inflammation in adolescents and young adults is likely linked to the vaccines, but that the benefits of the shots appeared to clearly outweigh the risk.
Moderna shares closed down 4.2%, while Pfizer fell 1.4%.
Pfizer, whose vaccine has been authorized for use in Americans as young as 12, said in a statement that it is aware of the reports of myocarditis and pericarditis after mRNA vaccination. It said that the benefit risk profile of the Pfizer/BioNTech vaccine “remains positive”.
Moderna said it is aware of reports of heart inflammation cases following administration of mRNA vaccines and is working with regulators.
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 U.S. Department of Health And Human Services, joined by leading U.S. 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.”
Dr. Sarah Long, professor of pediatrics at Drexel University College of Medicine, says “highly likely” that heart inflammation cases are related to COVID-19 vaccines.
The CDC is now admitting that post-second dose risk in people under 25 could be over 200x the background rate (and that’s not accounting for underreporting).