A health care worker holds a vial of the Pfizer COVID-19 vaccine at Jackson Memorial Hospital in Miami, in this Tuesday, Oct. 5, 2021, file photo. (AP Photo / Lynne Sladky, File)

Pfizer asked the U.S. government Thursday to allow use of its COVID-19 vaccine in children ages 5 to 11 in what would be a major expansion that could combat an alarming rise in serious infections in youngsters and help schools stay open.

If regulators give the go-ahead, reduced-dose kids’ shots could begin within a matter of weeks for the roughly 28 million children in that age group.

Many parents and pediatricians are clamoring for protection for youngsters under 12, the current age cutoff for COVID-19 vaccinations in the U.S.

The Food and Drug Administration will have to decide whether the shots are safe and effective in elementary school-age children. An independent expert panel will publicly debate the evidence on Oct. 26.

Pfizer and its German partner BioNTech said their research shows the younger kids should get one-third of the dose now given to everyone else. After their second dose, the 5- to 11-year-olds developed virus-fighting antibody levels just as strong as those that teens and young adults get from regular-strength shots.

While kids are at lower risk of severe illness or death than older people, COVID-19 does sometimes kill children — at least 520 so far in the U.S., according to the American Academy of Pediatrics. And cases in youngsters have skyrocketed as the extra-contagious delta variant has swept through the country.

While some mothers and fathers will no doubt take a hard stand against vaccinating their children, many parents of elementary students are eagerly awaiting authorization of the shots after 18 months of remote learning, COVID-19 scares and infections, mask debates and school quarantines.

They are looking forward to regular visits to grandparents again, worry-free playdates, vacations and the peace of mind of dropping children at school without the constant fear they will get sick. Principals are hoping the shots will allow schools to stay open and return to normal.

Sarah Staffiere of Waterville, Maine, said she can’t wait for her children to get vaccinated, especially her 7-year-old, who has a rare immune disease that has forced the family to be extra cautious throughout the pandemic.

“My son asked about playing sports. ‘After you’re vaccinated.’ He asked about seeing his cousins again. ‘After you’re vaccinated.’ A lot of our plans are on hold,” said Staffiere, a laboratory instructor at Colby College. “When he’s vaccinated, it would give our family our lives back.”

Gib Brogan of Wayland, Massachusetts, said he is constantly worried about getting a call from his 10-year-old son’s school about virus exposure or infection, and he is hoping his child can be vaccinated in time for the holidays.

“I know our school district has careful protocols and procedures in place,” he said, “but every time we send him off to school, I’m thinking, ‘Are we going to get a phone call?’”

Pfizer studied the lower dose in 2,268 volunteers ages 5 to 11 and said there were no serious side effects. The study isn’t large enough to detect any extremely rare side effects, such as the heart inflammation that sometimes occurs after the second dose of the regular-strength vaccine, mostly in young men.

Cindy Schilling, an elementary school principal in West Virginia, which ranks dead last among the states in the percentage of fully vaccinated residents, said she doesn’t think many parents will take their children to get the shot.

She said she often hears them say they are more concerned about the effects of the vaccine than COVID-19, mainly because they haven’t seen any young children get dangerously sick.

“Some parents are all for it and getting it for peace of mind,” she said, “but the majority of parents I’ve talked to will not be getting it.”

Heather Miller, a mother from Dexter, Maine, said no one in her family of six is rushing to get the vaccine. She said she wants to wait for follow-up studies on the formula.

“I’m not 100% against getting it eventually, but I kind of fall into the ‘not right now, wait and see’ category,” Miller said.

Offering shots to elementary school children would be another big expansion of the U.S vaccination drive at a time when many poor countries are desperately short of vaccine. The U.S. has just begun dispensing booster shots to tens of millions of senior citizens and other vulnerable Americans.

If the FDA authorizes emergency use of the kid-size doses, the Centers for Disease Control and Prevention will make a final decision, after hearing from its outside advisers.

To avoid mix-ups, Pfizer is planning to ship the lower-dose vials specially marked for use in children.

Moderna has requested FDA permission to use its vaccine in 12- to 17-year-olds and also is studying its shots in elementary school children. Both Pfizer and Moderna are studying even younger children as well, down to 6-month-olds. Results are expected later in the year.

“It makes me very happy that I am helping other kids get the vaccine,” said Sebastian Prybol, 8, of Raleigh, North Carolina. He is enrolled in Pfizer’s study at Duke University and doesn’t yet know if he received the vaccine or dummy shots.

“We do want to make sure that it is absolutely safe for them,” said Sebastian’s mother, Britni Prybol. But she said she will be “overjoyed” if the FDA clears the vaccine.