▶ Watch Video: Health officials encourage people to get new COVID-19 boosters and flu vaccines

The Food and Drug Administration announced Wednesday that it had granted emergency use authorization for updated COVID-19 vaccine boosters for Americans as young as 5 years old, and the Centers for Disease Control and Prevention officially signed off on their use. The boosters can be given at least two months after their previous shot of the vaccine.

“FDA’s authorization of updated (bivalent) COVID-19 vaccines for this younger age group, and CDC’s recommendation for use, are critical next steps forward in our country’s vaccination program—a program that has helped provide increased protection against severe COVID-19 disease and death,” CDC Director Dr. Rochelle Walensky said in a statement. 

“Since children have gone back to school in person and people are resuming pre-pandemic behaviors and activities, there is the potential for increased risk of exposure to the virus that causes COVID-19,” Dr. Peter Marks, the FDA’s top vaccines official, said in a statement.

The FDA said it had considered data on the immune response and safety from the shots in children who had gotten a booster of the previous formulation to make its decision.

These new bivalent shots are manufactured in a nearly identical process from Pfizer-BioNTech and Moderna, aside from adding in a component designed to target the BA.4 and BA.5 variants.

“As families across the country take part in fall festivities and plan for the upcoming holiday season, we aim to provide school-aged children with additional protection against the Omicron BA.4/BA.5 subvariants, which continue to account for more than 80% of cases in the U.S.,” Pfizer’s CEO Albert Bourla said in a statement.

Pre-ordering wrapped up last week for the new vaccines from Pfizer and BioNTech formulated for this younger age group. A spokesperson for Pfizer said they have the ability to ship up to 6 million doses for younger children within the coming week, following their final quality-control checks.

A spokesperson for the Department of Health and Human Services did not respond to a request for comment on how many shots were requested of the new Pfizer vaccines for younger ages.

Moderna’s booster for kids is simply a smaller dose of the same formulation that is already being distributed for older age groups, and did not need to be pre-ordered.

Compared to adults, a smaller share of children will be eligible to get the updated booster, because fewer have gotten the vaccine to begin with.

Only around 60.8% of adolescents 12 and older and 31.5% of children 5 and older have so far received even their first two COVID vaccine doses, according to CDC data.

Marks acknowledged that the virus “tends to be less severe in children than adults,” but warned that kids still faced a risk of hospitalization or long-term effects from the virus and would benefit from the shots.

The CDC recently estimated that some 86.3% of children in the U.S. have survived at least one COVID-19 infection, based on surveying for antibodies in blood samples.

“We encourage parents to consider primary vaccination for children and follow-up with an updated booster dose when eligible,” said Marks.

Wednesday’s decision leaves only children under 5 years old ineligible to receive the updated COVID booster.

Federal health officials have previously said they expected these shots could be made available for the next youngest age group, down to 6 months old, by the winter.

Moderna said Wednesday in a release that it expected to complete its application for emergency use authorization in this youngest age group “later this year.”