FDA asks Pfizer and Moderna to expand COVID-19 vaccine pediatric studies- NYT

July 26 (Reuters) - U.S. regulators have asked Pfizer Inc -BioNTech and Moderna Inc to expand the size of ongoing trials testing their COVID-19 vaccines in children aged between five and 11, the New York Times reported on Monday.

The Food and Drug Administration has indicated that the current strength of the studies was inadequate to detect the rare side effects, including myocarditis, an inflammation of the heart muscle, and pericarditis, an inflammation of the lining around the heart, the report said. (

The health regulator has asked the companies to include 3,000 children in their trials, almost double the original number of study participants, the report said, citing people familiar with the matter.

FDA, Pfizer and Moderna did not immediately respond to Reuters request for comment. (Reporting by Mrinalika Roy in Bengaluru; Editing by Shinjini Ganguli)