Hugs with friends. Birthday parties indoors. Pillow fights. School children who got their first COVID-19 shots Wednesday said these are the pleasures they look forward to as the U.S. enters a major new phase in fighting the pandemic.

Health officials hailed shots for kids aged 5 to 11 as a major breakthrough after more than 18 months of illness, hospitalizations, deaths and disrupted education.

Kid-sized doses of the Pfizer-BioNTech vaccine cleared two final hurdles Tuesday — a recommendation from CDC advisers, followed by a green light from Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention.

At a Decatur, Georgia, pediatrician’s office Wednesday, 10-year-old Mackenzie Olson took off her black leather jacket and rolled up her sleeve as her mother looked on.

“I see my friends but not the way I want to. I want to hug them, play games with them that we don’t normally get to,” and have a pillow fight with her best friend, Mackenzie said after getting her shot at the Children’s Medical Group site.

With the federal government promising enough vaccine to protect the nation’s 28 million kids in this age group, pediatricians’ offices and hospitals began inoculating children, with schools, pharmacies and other locations planning to follow suit in the days ahead.

The atmosphere surrounding the launch of shots for elementary-age students was festive in many locations. California vaccine sites welcomed children with kid-friendly motifs like inflatable animals and handed out coloring books and prizes. Vehicles lined up before dawn at an Atlanta site where a 10-year-old girl bounced around her family’s car in excitement.

Many pediatricians’ offices were expecting strong interest in the shots at least initially, but health officials are worried about demand tapering off. Almost two-thirds of parents recently polled by the Kaiser Family Foundation said they would wait or not seek out vaccines for their kids.

Brian Giglio, 40, of Alexandria, Virginia, brought his 8-year-old son, Carter, in for vaccination at Children’s National Hospital in Washington, D.C., where kids with underlying conditions got first dibs. Carter has Type 1 diabetes that puts him at risk for complications if he were to become infected.

Giglio said the vaccine was “like a hallway pass for us to begin living life again.” And Carter said he can’t wait to leave masks behind once he’s fully vaccinated, so he can smell the things he used to be able to smell without it.

“I’m ready to trash it,” he said, though the CDC still recommends masks in schools and indoor public spaces where virus activity is high, even for the fully vaccinated.

Cate Zeigler-Amon, 10, was first in line Wednesday for a drive-through vaccination at Viral Solutions in Atlanta. The girl enthusiastically bounced around the car before the shot, which she broadcast live on her computer during morning announcements at her elementary school.

Afterward, Cate said she was “very, very, very excited and very happy,” looking forward to hugging her friends and celebrating her birthday indoors next month “instead of having a freezing cold outside birthday party.”

Hartford Hospital in Connecticut vaccinated seven youngsters Tuesday night, minutes after CDC’s director gave the OK, and three more early Wednesday. One girl squeezed her eyes shut and a boy barely flinched as they got their shots and other waiting kids applauded.

The vaccine — one-third the dose given to older children and adults and administered with kid-sized needles — requires two doses three weeks apart, plus two more weeks for full protection. That means children who get vaccinated before Thanksgiving will be covered by Christmas.

“The timing before winter holidays is very fortunate,” said Dr. Jennifer Shu, whose Children’s Medical Group office in Decatur, Georgia, began vaccinating first thing Wednesday. “This age group will be able to spend holidays with friends and family more safely than they have been able to since the start of the pandemic.”

Thousands of pediatricians pre-ordered doses, and Pfizer began shipments soon after the Food and Drug Administration’s decision Friday to authorize emergency use. Pfizer said it expects to make 19,000 shipments totaling about 11 million doses in the coming days, and millions more will be available to order on a weekly basis.

Authorities said they expect a smooth rollout, unlike the chaos that plagued the national one for adults nearly a year ago.

Asked about parents having trouble finding vaccine appointments, White House coronavirus coordinator Jeff Zients said the vaccines.gov website will be updated by Friday for parents to search for locations near them. He said the kid vaccination campaign will be at full speed next week as Pfizer continues to ship millions more doses to locations around the country.

And he said more than 6,000 vaccination clinics are being planned at schools around the country before the winter holiday break.

Walgreens planned to start kids’ vaccinations Saturday and said parents could sign up online or by calling 1-800-Walgreens. CVS was also accepting appointments online and by phone at select pharmacies starting Sunday.

Despite the initial enthusiasm, not everyone is rushing out to get shots.

Hannah Hause, a Colorado mother of four children ages 2, 5, 7 and 8, is herself vaccinated, but wants to see how the child vaccines play out and are studied in the larger childhood population.

“It’s not studied long-term. It just makes me nervous,” she said. “As long as I can wait, I will wait.”

At a White House briefing Wednesday, Walensky authorities thoroughly reviewed all available data on the vaccine’s safety, efficacy and the immune response it generates before recommending shots for kids.

Government authorities said pediatricians and family doctors, whom parents depend on to give routine childhood vaccinations, could help build trust.

Dr. Ada Stewart, a Black family physician in Columbia, South Carolina, who works at a clinic for underserved patients, said she’s ready to start vaccinating younger children. She’s seen the toll the virus has taken on them — not just in family illness and death but with school disruptions, slipping grades and mental strain.

School closures throughout the pandemic have disproportionately burdened children of color, widening academic gaps and worsening mental health, according to data presented Tuesday to CDC advisers. It showed more than 2,000 COVID-related school closures in just the first two months of the current school year.

But Stewart thinks demand for kids’ shots will be mixed.

“Because many of my patients are Black, Indigenous and people of color, I’ve seen the full spectrum,’’ from parents eager to get their children vaccinated to those who are more hesitant “because of a history of mistrust in the medical community,’’ said Stewart, past president of the American Academy of Family Physicians.

Her message to both is the same: “Vaccines work, they’re safe, they’re effective and they save lives.’’

A Pfizer study of 2,268 children found the vaccine was almost 91% effective at preventing symptomatic COVID-19 infections. The FDA examined 3,100 vaccinated kids in concluding the shots are safe.

Some skeptics have questioned the need for kids to get vaccinated since they are less likely than adults to develop severe COVID-19. But with the delta variant, they get infected and transmit “just as readily as adults do,’’ Dr. Anthony Fauci said at a recent White House briefing.

Infected kids have also contributed to the U.S. toll — almost 46 million infections and more than 740,000 deaths.

Since the pandemic began, at least 94 children aged 5 to 11 have died from COVID-19, more than 8,300 have been hospitalized and over 5,000 have developed a serious inflammatory condition linked to the coronavirus. Black and Latino youngsters and those with chronic conditions are among the hardest hit.

But while some health authorities say minorities should be over-represented in COVID-19 vaccine studies because they are disproportionately affected by the virus, nearly 80% of kids in Pfizer’s study were white. Black youngsters totaled 6%, Latinos 21%, Asians 6% and less than 1% were American Indian or Alaska or Hawaii natives.

Kye’vontay Jordan, 7, who is Black, has diabetes and his shot at Children’s National in Washington, D.C., gave his dad peace of mind.

“Now I can sleep not worrying about him going to school,” said Brian Jordan. “Being exposed to the coronavirus could really affect him and mess him up.”

Patty Nieberg in Denver; Angie Wang in Washington, D.C.; Lauran Neergaard in Alexandria, Virginia, and Kate Brumback and Ron Harris in Atlanta contributed.

Follow AP Medical Writer Lindsey Tanner at @LindseyTanner.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.