A vial of the Pfizer-BioNTech COVID-19 vaccine at a vaccination clinic in the gymnasium of Antioch Middle School in Antioch, Calif., on May 19, 2021. (Eli Walsh/Bay City News)

The U.S. Food and Drug Administration gave its formal approval Friday of COVID-19 vaccines for children ages 5-11.

The FDA’s approval comes three days after an advisory panel to the regulatory agency voted 17-0, with one abstention, to authorize an expansion of the Pfizer-BioNTech vaccine’s emergency use authorization to include kids 5-11.

Clinical data presented to the FDA found that the vaccine was nearly 91 percent effective at preventing the virus among children ages 5-11. Roughly 3,100 kids in that age group were included the trial, which found no serious side effects among the vaccinated children.

“As a mother and a physician, I know that parents, caregivers, school staff, and children have been waiting for today’s authorization,” Acting FDA Commissioner Dr. Janet Woodcock said. “Vaccinating younger children against COVID-19 will bring us closer to returning to a sense of normalcy.”

The Pfizer vaccine will still be administered in two doses among children 5-11, but at one-third of the dose that has been administered to those ages 12 and up.

The vaccine’s use in young children will still require the approval of the U.S. Centers for Disease Control and Prevention, an advisory panel for which is expected to consider clinical safety and efficacy data early next week.

In California, Nevada, Oregon and Washington, the vaccine’s approval will face an additional hurdle in the form of the Western States Scientific Safety Review Workgroup.

The four-state group is on track to issue its own approval of COVID-19 vaccines for 5-11 year olds by Nov. 5 or 6.

COVID cases among those ages 5-11 make up 39 percent of cases in children, according to the CDC.

In addition, some 8,300 children ages 5-11 have been hospitalized with COVID-19 and 146 children in that age group have died due to the virus.