FDA delays assessment of Moderna COVID-19 vaccine for adolescents until January 2022

Last week, the U.S. Food and Drug Administration (FDA) notified Moderna, Inc. that an assessment of an emergency use authorization request for its COVID-19 vaccine to be used on adolescents may not be completed before January 2022.

The delay was due to a stated necessity to evaluate recent international analyses of the risk of myocarditis after vaccination. Myocarditis, or inflammation of the heart muscle, has been observed as an increased risk for several COVID-19 vaccines, particularly among young men after a second dose. Both the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) have labeled these side effects to be rare and generally mild. Still, concerns remain significant enough to demand further scrutiny.

Moderna is seeking authorization for mRNA-1273 at a 100 µg dose level for those between ages 12 and 17 years old. Adults are already authorized to utilize the vaccine.

“The safety of vaccine recipients is of paramount importance to Moderna,” the company said in a 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.”

So far, more than 1.5 million adolescents are estimated to have taken the Moderna COVID-19 vaccine. Based on its observations, the company has attested that there does not appear to be an increased risk of myocarditis in patients younger than 18 years old. However, the company admitted the FDA has greater access to recent international analyses than it does.

However, under a recent agreement with Gavi, the Vaccine Alliance, Moderna pledged to supply up to 116.5 million doses of mRNA-1273 worldwide in the second quarter of 2022 to benefit the 92 low and middle-income countries participating in the Gavi COVAX Advance Market Commitment. COVAX is a global initiative led by Gavi, the Coalition for Epidemic Preparedness Innovations (CEPI) and WHO, to pursue equitable COVID-19 vaccine access for all countries.

Under a previous agreement, Moderna had pledged 60 million doses of the vaccine. Gavi retains the option to procure another 233 million doses next year, which would bring the total doses from Moderna up to 500 million, provided at the company’s lowest tiered price.

While the FDA continues reviewing the request for the adolescent use of mRNA-1273, Moderna announced it will delay filing a request for another EUA, which would have allowed a 50 µg dose of mRNA-1273 to be used by children between 6 and 11 years old. That request will be delayed until the FDA’s review of the adolescent request is completed.