Very young children may be able to start receiving shots early next week.
The US Centers for Disease Control and Prevention on Saturday recommended Moderna's and Pfizer's COVID vaccines for all children 6 months through 5 years of age.
Earlier in the day, science advisers to the CDC voted unanimously to recommend the shots, and CDC Director Dr. Rochelle Walensky later approved the advisers' recommendation. The move expands eligibility for vaccination to nearly 20 million additional children, and parents could be able to start getting young kids their shots early next week.
"Together, with science leading the charge, we have taken another important step forward in our nation's fight against COVID-19," Walensky said in a statement. "We know millions of parents and caregivers are eager to get their young children vaccinated, and with today's decision, they can. I encourage parents and caregivers with questions to talk to their doctor, nurse, or local pharmacist to learn more about the benefits of vaccinations and the importance of protecting their children by getting them vaccinated."
All children, including kids who've already had COVID-19, should get vaccinated, the CDC said in a release, adding that COVID vaccines have been subjected to the most intensive safety monitoring in US history and will continue to be closely monitored.
The vote and Walensky's approval come a day after the vaccines were approved for emergency use by the Food and Drug Administration, which said it expected them to protect younger kids from the most serious outcomes of COVID-19, including hospitalization and death.
Pfizer's vaccines had previously been approved for use in children at least 5 years old, while the Moderna vaccine had only been approved for use in people ages 18 and up.
For most small children, the Moderna vaccines will be administered in two shots one month apart, though some kids with certain kinds of immunocompromise could receive a third shot at least one month after they get their second, the FDA said.
With the Pfizer vaccine, all kids ages 6 months through 4 years will get three shots, the first two of them three weeks apart, followed by a third dose at least eight weeks later.
The White House has said the vaccinations could start as early as Tuesday, though vaccine availability could vary state to state.
CNET's Bree Fowler contributed to this report.