After nearly two years without in-person shows, ballet companies all around the United States have been tiptoeing back into theaters.

But now they’re zooming in with the biggest show of most seasons, Nutcracker, which features large casts of children and adults. Troupes count on this ballet for a majority of their annual budget, and it’s a holiday tradition for so many people who never otherwise get to an opera house.

Nutcracker this year had long been a goal, yet how to perform it safely was still a big question mark. In early fall, when most companies were auditioning young ballet students, COVID-19 vaccines were not yet available for children under 12, which is about the age when some students grow too tall for the children’s roles.

But Philadelphia Ballet artistic director Angel Corella made a bet that vaccines would soon be approved for younger children, so he cast them as usual — and the bet paid off.

“We’re going to keep the company separated from the School [of Philadelphia Ballet] until the very last week” of rehearsals, Corella said in mid-November. Everyone would be masked in classes and rehearsals, but the masks would come off as dancers stepped on stage at the Academy of Music. Performances begin on Friday.

“They’re getting incredibly incredible stamina” by dancing with a mask, Corella said. “Because when they take the mask off, they’re like flying.

“Everyone in the company has been vaccinated,” he said. “So we have 100% vaccination, and the orchestra as well. Most of our kids, they already have the first doses. So hopefully we’ll have two doses.

“But what we are going to do is, whoever is vaccinated, they will be tested twice a week during the performance while we are at the theater. If the kid is not vaccinated, then they have to test every time they go into the theater.”

Jaslene Scott, 13, of Wilmington, Del., is excited to be back performing Nutcracker. She has danced most of the children’s roles since she started at the School of Philadelphia Ballet in 2016 and is a candy cane this year, the last role most children dance before they’re too tall to participate.

She got vaccinated in June, after her mother used ballet as motivation.

“I said to her, ‘What if the school says you can’t dance without being vaccinated?’ ” said her mother, Oriel Harris. “So we went around that day and she got the vaccine.”

Emerson Lomba, 9, from Haddon Township, is playing Fritz and is also vaccinated. He started at the School of Philadelphia Ballet shortly before shutdown in 2020. He is eager to finally perform in Nutcracker.

Lomba went to the audition figuring he was going to be cast as a boy in the party scene. “We all thought I was too tall for fridge. And then I got Fritz, though, and we were all shocked and excited — and amazed that I had the opportunity to be Fritz and work with the Philadelphia Ballet.”

One fail-safe Corella decided to do was to hire an additional cast of children who would rehearse in a separate location. The main children’s characters — Marie, the Prince, and Fritz — all come from the School of Philadelphia Ballet. But for the rest of the children’s roles, Philadelphia Ballet partnered with the Metropolitan Ballet Academy, and their students rehearsing in its Jenkintown studio.

Each set of dancers will dance a number of performances. But if a child were to test positive for COVID-19, the company could replace the entire cast from one school with the one from the other school. The children and parents have been notified to be on call.

Even with the omicron variant arriving in Philadelphia, Philadelphia Ballet is forging ahead. Tickets have sold briskly, with some going for more than face value on third-party sites. The Academy of Music is expected to be at least 70 percent full for all performances, with the goal of full houses. Opening night is sold out. Plans would only change if the CDC, city, or Kimmel Center change COVID-19 recommendations, said Philadelphia Ballet publicist Roger Lee.

Other companies have taken other approaches. New York City Ballet opted to cast older kids this year. They removed the usual height requirements and created all new children’s costumes — at a cost of $375,000, said Kina Poon, manager of media relations for City Ballet.

Corella said Philadelphia Ballet considered this approach, too, but he decided it would be too expensive and worried the children would look too grown up. “We would have to pretty much have to redo the whole first act costumes,” he said.

Pacific Northwest Ballet, in Seattle, took another approach. The company members, all vaccinated, would remove their masks just prior to stepping on stage. For the children, their costume shop made masks to match the costumes, a separate mask for each child. These cost about $3,250, said Gary Tucker, PNB’s director of communications.

The other major change audiences will notice is the absence of the red-coated Philadelphia Boys Choir, which normally sings during the snow scene.

“It would be impossible to keep it to keep them safe,” Corella said.

The theater will open 45 minutes before showtime rather than the usual 30, to allow time to check vaccine cards or negative test results.

Nutcracker is a perfect test to see if the people are ready to go back” to the theater,” Corella said. “We’re starting to see that they are.”

Scott is looking forward to returning to the stage. The best Nutcracker moments, she said, are the little ones.

“Like waiting to be on stage, like that little rush before going on stage, like listening to the music and counting the counts of the other dances with your friends, and waiting on the wing.”

Or getting changed into costumes and listening for a cue. “We’ll count the music, like when you hear Drosselmeier come on stage, or when you hear the music for a character to come on,” Scott says. “You’re waiting and everyone says, ‘OK, everybody got on stage, there was a music change, there was a count change, everybody get in your spot.’”

And then it’s go time.

DANCE

Philadelphia Ballet in “George Balanchine’s The Nutcracker”

Dec. 10-31, Academy of Music

Tickets: $25-$224

Information: 215-893-1999 or philadelphiaballet.org.