FDA delays decision on Moderna COVID-19 vaccine for kids 12-17

CAMBRIDGE, Mass. - A decision on the authorization of Moderna’s COVID-19 vaccine for kids ages 12 to 17 has been delayed while U.S. regulators continue to study the rare risk of heart inflammation, the company said Sunday. 

The U.S. Food and Drug Administration told Moderna on Friday evening that its review could last until January, according to a company statement. Moderna also said it will delay filing a request for emergency-use authorization of a lower dose of the vaccine for 6- to 11-year-olds.

"The safety of vaccine recipients is of paramount importance to Moderna," the company said in the statement. "The company is fully committed to working closely with the FDA to support their review and is grateful to the FDA for their diligence."

Heart inflammation, called myocarditis, is an exceedingly rare risk of both the Pfizer and Moderna vaccines. It is more commonly seen in young men or boys and after the second dose. It’s also difficult for clinical trials to detect such a rare problem.

Public health officials have repeatedly stressed that COVID-19 itself can cause heart inflammation at higher rates than the rare cases caused by the vaccine. Meanwhile, pediatricians and many parents are clamoring for protection for younger children as the extra-contagious delta variant has surged and caused an alarming rise in pediatric infections.

FILE - A high school student gets vaccinated against COVID-19 with Moderna during a vaccination campaign on Sept. 13, 2021, in Berlin, Germany. (Photo by Bernd von Jutrczenka/picture alliance via Getty Images)

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Moderna said more than 1.5 million adolescents are estimated to have received its COVID-19 vaccine around the world. It said the observed rate of heart inflammation in those under 18 "does not suggest an increased risk" in this population.

In the U.S., the Moderna vaccine is authorized for people 18 and older. U.S. children from 12 to 17 can get the vaccine produced by Pfizer and its partner BioNTech.

Last week, the FDA moved to allow the use of Pfizer shots in children between 5 and 11 — a key step in rolling out the shots to younger children. The agency’s panel of outside previously experts voted unanimously — with one abstention — that the vaccine’s benefits in preventing COVID-19 in younger kids outweighed any potential risks, which included questions about the rare heart-related side effect.

A panel of advisers to the U.S. Centers for Disease Control and Prevention is debating Pfizer’s shot for kids 5 to 11 this week. 

RELATED: Pfizer COVID-19 vaccine for children likely won't be available until November 

Moderna also has been testing two shots, one month apart, for children 6 to 11, at half the dose given to adults. Last week, the company shared interim data from its Phase 2/3 study, which showed that two smaller doses of its COVID-19 vaccine were generally well-tolerated in more than 4,750 children. 

One month after the second dose, participants in Moderna’s trial had antibody levels that were 1.5 times higher than those observed in young adults, the company said.

RELATED: Moderna says COVID-19 vaccine generates 'robust' response in kids 6-11 

This story was reported from Cincinnati. The Associated Press contributed.