Melody Figueroa, 6, holds her mother Judy Chow, as she get her first COVID-19 vaccine at Katherine R. Smith Elementary School, in San Jose, Calif., on Nov. 4, 2021. (Harika Maddala/Bay City News)

Children ages 5-11 are now eligible to receive a booster COVID-19 vaccine dose following Tuesday’s approval by the U.S. Food and Drug Administration.

With the approval, all vaccine-eligible age groups are now also eligible for at least one booster vaccine dose. Kids ages 5-11 will become eligible for a booster if they completed their initial vaccination series at least five months prior.

Health experts have said that boosters are necessary to bolster a vaccinated person’s immune response to the virus, as protection from the initial vaccine series wanes after four-to-six months.

“While it has largely been the case that COVID-19 tends to be less severe in children than adults, the omicron wave has seen more kids getting sick with the disease and being hospitalized, and children may also experience longer term effects, even following initially mild disease,” FDA Commissioner Dr. Robert Califf said.

Federal regulators authorized COVID-19 vaccines for children ages 5-11 last October after trial data found that the two-dose Pfizer-BioNTech vaccine was nearly 91 percent effective at preventing the virus among children in that age group.

That trial included roughly 3,100 children and found no serious side effects among those who received the vaccine.

The Pfizer vaccine is the only COVID vaccine authorized for emergency use for children under age 16. Federal regulators have given their full approval for the Pfizer vaccine, marketed under the name Comirnaty, for people ages 16 and up.

As of Tuesday, 35 percent of children ages 5-11 in California have completed their initial vaccination series, according to data from the California Department of Public Health.

Overall, 75.2 percent of California residents ages 5 and up have completed their first series.

“Vaccination continues to be the most effective way to prevent COVID-19 and its severe consequences, and it is safe,” Califf said. “If your child is eligible for the Pfizer-BioNTech COVID-19 Vaccine and has not yet received their primary series, getting them vaccinated can help protect them from the potentially severe consequences that can occur, such as hospitalization and death.”