Younger children could soon be eligible to receive an updated Covid-19 booster shot.

Pfizer and BioNTech on Monday said they completed their submission to the US Food and Drug Administration for emergency use authorization of their updated Covid-19 booster for children ages 5 through 11. Moderna on Friday said it had requested FDA authorization for its updated booster for adolescents ages 12 to 17 and for children ages 6 to 11.

Like the boosters that became available for older people earlier this month, these bivalent boosters target the original coronavirus strain as well as the Omicron BA.4/BA.5 subvariants.

Pfizer’s updated booster is currently authorized for use in people 12 and older and Moderna’s is authorized for adults age 18 and older.

Pfizer said on Monday it has initiated a Phase 1/2/3 study of the safety, tolerability and immunogenicity of the vaccine in people ages 6 month to 11-year-olds has also been initiated.

Moderna tweeted that its authorization application for an updated booster for children ages 6 months through 5 years is expected later this year.

Currently, people too young to receive an updated booster can still be boosted with earlier versions of the Covid-19 vaccines.

Millions of updated boosters administered

Data released Thursday by the US Centers for Disease Control and Prevention shows that about 4.4 million people have gotten a dose of the updated Covid-19 boosters.

The total does not reflect doses given in Idaho and Texas because of the way those states report vaccinations. The agency says it’s working to incorporate that information.

For now, people 12 and older who’ve had their primary vaccine series are eligible to get the updated boosters, which replace the original boosters in those age groups. People who have recently had Covid-19 may want to wait at least three months, as infection itself can act as a booster.