The FDA told Moderna it needs more time to review use of their COVID-19 vaccine for kids

• Use of Moderna's vaccine in kids 12 to 17 years old will most likely be delayed to early next year.
• The drug company said the FDA told them they needed more time to review.

The Food and Drug Administration on Friday told Moderna it needed more time to review a rare heart risk from COVID-19 vaccines in youths before it could allow the emergency use of the vaccine in people between the ages of 12 and 17, the drug manufacturing company said on Sunday.

Moderna said the FDA told them they need more time to review the risk of possible myocarditis - a heart muscle inflammation - after vaccination, which could delay approval until after January 2022.

"The Company is fully committed to working closely with the FDA to support their review and is grateful to the FDA for their diligence," the company said in the statement.

The Wall Street Journal reported that myocarditis is usually caused by a viral infection and could lead to an abnormal heartbeat, heart failure, and in extreme cases, death.

The Centers for Disease Control and Prevention said there have been reports of the heart condition after mRNA vaccination, mostly in adolescent and young adult males, a few days after the second dose. The CDC added that in most cases, those who developed the condition responded well to medicine and felt better quickly.

The Journal added that the condition is much more common in children who get COVID-19 then developing it after vaccination.

Moderna also said it's committed to "conducting its own careful review of new external analyses as they become available."