Citing concerns about the risk of heart inflammation associated with the vaccines, the U.S. Food and Drug Administration asked Pfizer and Moderna to expand the number of children in their clinical trials.
Pfizer and Moderna will increase the number of children in their COVID vaccine clinical trials prior to seeking Emergency Use Authorization (EUA), after the U.S. Food and Drug Administration (FDA) told the vaccine makers the size and scope of their pediatric studies, as initially envisioned, were inadequate to detect rare side effects.
The rare side effects cited by the FDA include myocarditis, an inflammation of the heart muscle, and pericarditis, inflammation of the lining around the heart, multiple people familiar with the trials told The New York Times.
Moderna’s shot is authorized for emergency use in people 18 and up, and Pfizer’s vaccine is authorized for children as young as 12. No COVID vaccines have yet received EUA approval for children younger than 12.
Expanding the pediatric trials means thousands more children as young as 6 months old may soon be recruited and enrolled in COVID vaccine trials.
According to the Times, the FDA asked the companies to include 3,000 children in the 5- to 11-year-old group, the group for whom results were expected first.
One person, granted anonymity by the Times to speak freely, described that figure as double the original number of study participants.
Read More: At FDA Urging, Pfizer and Moderna to Include Thousands More Children in Clinical Trials