A pharmacist holds a vial of the Moderna coronavirus disease (COVID-19) vaccine in West Haven, Connecticut, U.S., February 17, 2021.
A pharmacist holds a vial of the Moderna coronavirus disease (COVID-19) vaccine in West Haven, Connecticut, U.S., February 17, 2021. Reuters / Mike Segar

Advisers to the U.S. Food and Drug Administration on Tuesday recommended that the agency authorize Moderna Inc's COVID-19 vaccine for children and teens aged 6 to 17 years of age.

The FDA's Vaccines and Related Biological Products Advisory Committee, comprised of outside experts, voted unanimously in favor of making the vaccine available for that age group.

Around 77 million people in the United States have received at least a two-dose course of Moderna's vaccine, which has long been available for people aged 18 and older.

The committee is scheduled on Wednesday to consider the Moderna shot for children ages under 6, and Pfizer and BioNTech's COVID vaccine for children under 5 - and in both cases as young as 6 months.

There is unlikely to be significant immediate demand the Moderna shots for 6- to 17-year olds. The Pfizer/BioNTech vaccine was authorized for children aged 5 to 11 in October, and approval for teenagers preceded that by months.

Yet only around 30% of those ages 5 to 11 and 60% of 12- to 17-year olds are fully vaccinated in the United States, according to data from the U.S. Centers for Disease Control and Prevention (CDC).

The FDA - which generally follows the recommendations of its advisers but is not obligated to do so - is liklely to authorize the Moderna vaccine for ages 6-17 soon. The CDC also needs to recommend the vaccine's use. A committee of its advisers is scheduled to meet Friday and Saturday.

There have long been concerns that the Moderna vaccine, which is given at a higher dose than the Pfizer/BioNtech shot, may cause types of heart inflammation known as myocarditis and pericarditis at higher rates, primarily in younger males.

Some countries in Europe have limited use of Moderna's vaccine for younger age groups after surveillance suggested it was tied to a higher risk of heart inflammation, and the FDA delayed its review of the shot to assess the myocarditis risk.

U.S. regulators presented data at the meeting on Tuesday suggesting that Moderna's vaccine may have a higher risk of heart inflammation in young men, but said the findings were not consistent across various safety databases and were not statistically significant, meaning they might be due to chance.