RALEIGH, N.C. (WNCN) – The FDA’s review of Moderna’s vaccine for children was put on hold. The company said in a statement that the FDA said it needed more time to consider a rare side effect that impacts the heart.

This rare side effect is called myocarditis — a swelling of the heart muscle. It’s most often seen in young men and boys after their second dose.

It’s one of the biggest topics of discussion for the FDA and CDC when considering COVID-19 vaccines for children. Moderna said in a statement, “the agency requires additional time to evaluate recent international analyses of the risk of myocarditis after vaccination. The FDA notified Moderna that this review may not be completed before January 2022.”

That data isn’t public right now.

“What we have seen when we’ve taken a look and a deep dive on these cases is that by and large, they are nearly exclusively all mild, and all recover with absolutely no untoward effect,” said Dr. Christina Johns, senior medical advisor and pediatrician for PM Pediatrics.

She said the possibility of myocarditis is real but rare.

“It is a lower risk of myocarditis from the vaccine than it is from COVID-19 infection itself,” Johns said.

CDC has shown the risk of myocarditis from a COVID-19 infection is 0.2 percent. The risk of it from the vaccine is even smaller at 0.01 percent for males ages 12 to 17.

Johns said COVID-19 vaccines can protect children from more common, long-term symptoms infection can cause.

“They are having trouble focusing and concentrating. They are having a migraine headache, sometimes heart palpitations,” Johns described.

Johns said having questions is normal and your child’s pediatrician is your greatest resource right now.

“That person is really the best trained to curate all of the sea of information that we are hearing what’s online and what is in science journals. They’re the ones who know your child the best along with you,” she said.

While the decision on Moderna’s child vaccine is on hold for now, a CDC advisory committee is making its decision on Pfizer’s pediatric shot on Tuesday.