(NewsNation Now) — U.S. health officials on Tuesday gave the final signoff to Pfizer’s kid-size COVID-19 shot for children ages 5 to 11.

The announcement by CDC director Dr. Rochelle Walensky came only hours after an advisory panel unanimously decided Pfizer’s shots should be opened to the 28 million youngsters in that age group.

The Food and Drug Administration cleared kid-size doses — just one-third the amount given to teens and adults — for emergency use last week.

With the FDA’s action, Pfizer had already begun shipping millions of vials of the pediatric vaccine — in orange caps to avoid mix-ups with the purple-capped doses for everyone else — to doctors’ offices, pharmacies and other vaccination sites. Kids will get two shots, three weeks apart.

While children are at lower risk of severe illness or death from COVID-19 than older people, 5- to 11-year-olds still have been seriously affected — including over 8,300 hospitalizations, about a third requiring intensive care, and nearly 100 deaths since the start of the coronavirus pandemic, according to the FDA.

And with the extra-contagious delta variant circulating, the government has counted more than 2,000 coronavirus-related school closings just since the start of the school year, affecting more than a million children.

Nearly 70% of 5- to 11-year-olds hospitalized for COVID-19 in the U.S. have other serious medical conditions, including asthma and obesity, according to federal tracking. Additionally, more than two-thirds of youngsters hospitalized are Black or Hispanic, mirroring long-standing disparities in the disease’s impact.

A Pfizer study of 2,268 schoolchildren found the vaccine was nearly 91% effective at preventing symptomatic COVID-19 infections, based on 16 cases of COVID-19 among kids given dummy shots compared to just three who got vaccinated.

The kid dosage also proved safe, with similar or fewer temporary reactions — such as sore arms, fever or achiness — than teens experience.

But the study wasn’t large enough to detect any extremely rare side effects, such as the heart inflammation that occasionally occurs after the second full-strength dose, mostly in young men and teen boys. It’s unclear if younger children getting a smaller dose also will face that rare risk.

The similarly made Moderna vaccine also is being studied in young children, and both Pfizer and Moderna also are testing shots for babies and preschoolers.