By Jared S. Hopkins and Betsy McKay

A federal advisory panel recommended that 12- to 15-year-olds receive the Covid-19 vaccine from Pfizer Inc. and BioNTech SE, an important step toward expanding the nation's vaccination campaign.

The Advisory Committee on Immunization Practices, or ACIP, which advises the Centers for Disease Control and Prevention on vaccination policy, voted to recommend the vaccine at a meeting Wednesday after reviewing clinical trial data and other relevant information. The vote was 14-0, with one voting member recusing.

Many parents, school officials and health authorities are eager for children to receive vaccinations in time for summer camps and the start of the next school year. Health authorities expect children to be vaccinated at pharmacies, physician offices and existing mass-vaccination sites.

Vaccinations of adolescents have already begun in some parts of the country, but most shot providers were waiting for a formal recommendation from ACIP. The committee recommendation would become policy when the CDC's director, Dr. Rochelle Walensky, signs it.

"This is another way to get closer to ending this horrible pandemic," said Dr. Camille Kotton, an infectious-disease specialist at Massachusetts General Hospital in Boston and ACIP voting member.

Expanding vaccination to children is necessary to slow the spread of Covid-19 and move the country beyond the pandemic, allowing full returns to school, work and commerce, public-health officials say. There are nearly 17 million children ages 12 to 15 in the U.S., according to the Kaiser Family Foundation, a health nonprofit.

The 15-member advisory panel consists of pediatricians, infectious-disease doctors and other medical experts. The panel's recommendation follows the Food and Drug Administration's authorization Monday of the two-dose Pfizer-BioNTech shot for use in children as young as 12 years old, the first Covid-19 vaccine for children in the nation.

"This will provide protection for 12- to 15-year-olds," said Dr. Henry Bernstein, a voting member of ACIP and professor of pediatrics at Zucker School of Medicine at Hofstra/Northwell. "It will decrease transmission within their families. It will contribute to community immunity, and it will allow the kids to more safely go back to camps this summer and back to in-person school."

Children are at lower risk of Covid-19 infection than adults, according to health experts, and when infected tend to experience milder symptoms. Yet some children can become seriously ill and some can spread the virus.

At Wednesday's meeting, ACIP members discussed the results of the Pfizer-BioNTech study of 2,260 adolescents that found the two-dose shot was 100% effective at protecting against symptomatic Covid-19 in 12- to 15-year-olds.

In the trial, about half of the subjects received doses of vaccine three weeks apart, while the rest of the subjects received placebos. The volunteers who got the vaccine received the same dose that older people get.

Researchers found 12- to 15-year-olds who received the vaccine generated an immune response similarly strong as in 16- to 25-year-olds.

So far, researchers haven't found evidence the vaccine poses any additional or different risks to children versus adults. The most common side effects of the vaccine are flulike symptoms such as fever, muscle aches and chills, and they were at similar rates found in 16- to 25-year-olds, according to the CDC and Pfizer.

Seven children who were vaccinated experienced swollen or enlarged lymph nodes due to the vaccine, compared with one subject in the placebo group, according to Pfizer and the CDC.

Five children who received the vaccine experienced serious side effects, compared with two in the placebo group, said John Perez, Pfizer's vice president of clinical research and development. In the vaccinated group these included four cases of psychiatric disorders, including depression, anxiety and suicide ideation, and Dr. Perez said these children either had a history of depression or were prescribed medication for related disorders before the trial. One child in the vaccinated group also experienced stomach pain and constipation, and nerve pain.

None of the serious side effects were found to be linked to the vaccine, according to the CDC.

Pfizer hasn't yet analyzed the data by race or ethnicity, said Dr. Perez. About 85% of the subjects in the trial were white.

Covid-19 cases are rising in adolescents, and as older Americans have gotten vaccinated, adolescents make up an increasing proportion of the overall U.S. case count, Sara Oliver, a CDC medical officer, said. Adolescents accounted for 9% of reported cases in April, a larger proportion than cases involving people 65 years and older as more adults have been vaccinated, she said.

More than 1.5 million children ages 12 to 17 have been diagnosed with Covid-19 since March 2020 and more than 13,000 have been hospitalized, CDC data show. Millions of cases go unreported, though, Dr. Oliver said. The agency estimates that 22.2 million children ages 5 to 17 have been infected since February 2020, making up about 19% of all infections.

Hospitalizations among 12- to 17-year-olds are far higher for Covid-19 than for influenza, CDC data show, and adolescents suffer more severely from a rare Covid-19 complication known as multisystem inflammatory syndrome in children, or MIS-C, than younger children. Covid-19 made up 1.3% of all deaths among 12- to 17-year-olds between Jan. 1, 2020, and April 30 this year. That level would have put it in the top 10 causes of death among children in 2019, Dr. Oliver said.

The Pfizer-BioNTech vaccine has become the most widely used shot in the U.S. since regulators cleared it in December for use in people 16 years and older after a trial involving 44,000 subjects.

The companies' vaccine is among three authorized for use in the U.S., along with shots from Moderna Inc. and Johnson & Johnson.

Pfizer anticipates asking the FDA in September to authorize its vaccine's use in children 2 to 11 years old should ongoing studies prove positive. The company said It plans to make a similar request for children 6 months to 2 years of age in the fourth quarter.

CDC officials also said during the meeting that people could receive Covid-19 vaccines the same day as other vaccines, or within two weeks of another vaccine. Since authorization, the shots have been administered to people if they weren't given other vaccines within two weeks.

Pediatricians have been monitoring for such a change because children may be able to get more than one vaccine when they visit physicians. Many children fell behind on vaccinations during the pandemic, according to federal officials.

Wednesday's recommendation is a reminder of the toll that the pandemic has taken on America's youth, said Grace Lee, an ACIP voting member who is a pediatric infectious-disease specialist at Stanford University. "I think the childhood experience our kids have gone through will have long-lasting consequences that may extend across generations," she said. "To be honest, we don't really fully yet understand the total physical health, mental health and educational impact of the pandemic on our kids."

Write to Jared S. Hopkins at jared.hopkins@wsj.com and Betsy McKay at betsy.mckay@wsj.com

(END) Dow Jones Newswires

05-12-21 1701ET