Pfizer/BioNTech (NYSE:/PFE, Nasdaq BNTX) and Moderna (Nasdaq:MRNA) have both won emergency use authorizations in the U.S. for bivalent vaccine boosters based on BA.4/BA.5.

Pfizer is aiming to win authorization to use its updated COVID-19 vaccine in children aged 5 through 11 years. Moderna has requested that FDA greenlight the use of its omicron booster in individuals 6 to 17.

Pfizer’s shot is currently authorized for individuals at least 12 years old, while Moderna’s is authorized for individuals 18 and up.

Pfizer noted in a news release that it had submitted safety and immunogenicity data for the bivalent BA.1-adapted vaccine to FDA. The company also included preclinical and manufacturing data related to the bivalent omicron BA.4/BA.5-adapted vaccine.

Moderna’s updated booster for adults includes a 50-µg dose of mRNA, while the Pfizer-BioNTech booster includes a 30-µg quantity of mRNA for individuals 12 and older.

For children aged 5 to 11, Pfizer and BioNTech are seeking authorization for a 10-µg booster dose of the Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine for children aged 5-11

Moderna is asking FDA to authorize a 50-µg dose for children under 12 to 17, while children 6 to 11 would receive a 25-µg dose.

Pfizer and BioNTech are currently running a Phase 1/2/3 study NCT05543616 (C4591048) to evaluate their BA.4/BA.5.–based bivalent booster.

CDC has signaled that the federal government could make omicron-adapted boosters available to children in mid-October, assuming the FDA agrees to extend emergency use authorization to younger age groups.

CDC plans on convening its vaccine advisory committee on October 19 and 20.

According to CDC data, about 4.4 million individuals in the U.S. have received updated COVID-19 boosters to date.

In January, CDC’s Advisory Committee on Immunization Practices (ACIP) voted nearly unanimously to authorize an earlier version of the Pfizer-BioNTech COVID-19 vaccine booster for individuals aged 12 to 17.

That figure represents less than 2% of the public who are eligible.

Moderna’s shares were down 2.28% to $120.82 in afternoon trading. PFE shares were mostly flat, ticking down 0.60% to $43.82, while BNTX shares were up 0.16% to $$128.56.