In order to get to the Beijing Olympics, Tabitha Peterson and her teammates had to pass a pair of high-stakes tests. They handled both with sure hands and steady nerves, making their way to the Winter Games in women's curling by capturing a bronze medal at the world championships and winning the U.S. Olympic trials.

It's been a little harder to control their anxiety over their next big tests. Every day in Beijing, everyone on Team Peterson will have their throats swabbed to check for COVID-19, knowing a positive result could sweep them out of the Olympics and into an isolation facility.

"Since omicron has been spreading like crazy, we've been a little freaked out,'' said Peterson, of Eagan. "We're just like, 'Oh, my God. Do not get it.' It's always in the back of your mind.''

Just six months after the pandemic-delayed Tokyo Summer Games, the Olympics are back— and not much has changed. COVID is crashing the party again at the Beijing Winter Games, which officially begin with Friday's Opening Ceremony.

As in Tokyo, these Olympics will be a masked-up, locked-down and socially distanced affair. That's just the starting point. With more contagious variants now circulating around the globe, organizers have adopted more stringent COVID protocols for about 3,000 athletes, as well as thousands of staff, volunteers and media.

Beijing organizers have created a "closed loop'' encircling all Winter Games venues and accommodations, a virtual Great Wall separating the Olympics from the rest of the city. Getting into the loop requires a vaccination, or for those receiving a limited medical exemption, a three-week quarantine. Staying there means a daily ritual of testing and wearing high-grade masks at all times.

And getting out? That's strictly forbidden, except for those leaving China — and those receiving a positive test result. Anyone who gets that grim news will be sent to an isolation hotel until they are cleared for release, a nightmare scenario for athletes who put in years of training for their Olympic moment.

"It would be silly to pretend that's not a stress,'' said Jessie Diggins of Afton, who is set to compete at her third Olympics in cross-country skiing. "The variants are everywhere. It seems like every day, you hear about an athlete getting sick, and that's hard.''

Several countries reported positive tests last week among athletes preparing to travel to Beijing. Two cross-country skiers from Norway were forced to isolate in Italy, and it's uncertain if they will make their Olympic races. A Russian figure skater was removed from the team after a positive test, while other athletes are waiting to see if they will be allowed to compete.

Many of the 30 U.S. athletes with Minnesota ties have taken whatever precautions they can. Curling skip John Shuster, the Chisholm native and defending Olympic gold medalist, pulled his young sons out of school so they would not bring the virus home. Teammate Chris Plys has self-quarantined for the past two weeks, going only to curling practice and the grocery store.

"There is so much anxiety,'' said Plys, of Duluth. "I'm going to be very relieved when we get to China and have a couple of negative tests.''

COVID's long shadow

Beijing hosted the Summer Olympics in 2008, making it the first city to stage both a Summer and Winter Games. It won the bid for the 2022 Games by only four votes over Almaty, Kazakhstan, after all other potential hosts dropped out of the race.

China remains a controversial pick, as it was in 2008. Its treatment of the Uyghur Muslim population — labeled a genocide by the U.S. — and its intolerance for dissent have stirred outrage from human-rights advocates and calls for a boycott. Though no countries are skipping these Olympics for political reasons, the U.S. is among a handful of nations refusing to send government officials.

The pandemic's unrelenting grip cast another shadow over the Games. After COVID-19 put the Tokyo Olympics on hold for a year, Beijing Olympics organizers and the International Olympic Committee were determined to stay on schedule, insisting they could hold the Winter Games safely.

China has enforced a zero-COVID policy since the pandemic began, shutting its borders and locking down entire cities to halt outbreaks. The Olympics' closed loop follows a similar philosophy.

"It is completely closed off from the world outside,'' said Pierre Ducrey, the IOC's director of operations for the Olympic Games. "There is no contact between people inside and outside the loop. Should there be any outbreaks, we are very much protected inside the loop.''

According to Ducrey, 33 athletes were unable to compete at the Tokyo Games because of positive COVID tests. Participants were tested every one to three days, they were not required to be vaccinated, and their movements were restricted for their first 14 days in Japan. Masks were mandatory, but any kind could be worn.

All those protocols were ratcheted up for Beijing. Everyone is required to test daily and wear high-grade masks like KN95s or N95s (athletes can remove their masks for competition and during medal ceremonies). Everyone is barred from going anywhere other than their accommodations and Olympic venues.

With a 21-day quarantine awaiting the unvaccinated, nearly everyone entering the loop is expected to have their shots. The U.S. Olympic & Paralympic Committee mandated vaccines last fall for all athletes competing in the Beijing Games. In Tokyo, about 100 athletes in a U.S. delegation of more than 600 were not vaccinated.

"There are some people who are extremely happy we introduced this policy,'' said Dr. Jonathan Finnoff, chief medical officer for the USOPC. "There are others that are upset and would like to not have any type of mandate regarding vaccinations. But I would say the latter is a very small minority.''

Back in a bubble

These Olympics will sprawl over a wide area, with three competition zones connected by a new high-speed train. The snowboarding, cross-country skiing and biathlon venues are among the farthest from Beijing, 112 miles away in the Zhangjiakou Zone. Alpine skiing and sliding sports are in the Yanqing Zone, 45 miles from the city center.

The Beijing Zone will host indoor events and ceremonies, using 2008 Summer Games venues for some. The Water Cube where swimmer Michael Phelps won eight gold medals is now the Ice Cube curling arena. The Opening and Closing ceremonies are in National Stadium, known as the Bird's Nest.

Unlike Tokyo, which barred all spectators, Beijing organizers hoped to open the Games to Chinese fans. They had to cancel those plans when omicron cases were found in China last month, but they still expect to allow some invited guests. For the second Olympics in a row, no families or friends are permitted to travel to support the athletes.

Peterson has played in a bubble environment before, at last year's world championships in Calgary. Trading a livelier atmosphere for a safer one is fine with her.

"As caseloads surged, the fact that [Beijing organizers] were allowing spectators did make me nervous,'' Peterson said. "I'm kind of happy they changed their minds.''

Like many athletes, Peterson created her own bubble in the weeks before her trip, practicing during slow hours at the St. Paul Curling Club and wearing KN95 masks whenever she left her house. The IOC reported that during its first two weeks inside the Beijing loop, 1.53% of people arriving at the airport tested positive, and screening tests of people inside the loop had a 0.02% positivity rate.

U.S. biathlete Leif Nordgren, a native of Marine on St. Croix, has been living with teammates in Europe while competing on the World Cup circuit. His team created its own safety protocols, which has given him some peace of mind.

"As long as we follow the rules we've laid down, which everyone is doing, I think we should be pretty good,'' he said. "We're trying not to freak out and make it a bigger deal than it already is.''

That's been the motto of the U.S. cross-country ski team, too. Diggins said she feels sad for her 10 teammates competing in their first Olympics, because they won't get a normal Winter Games experience.

She will miss hanging out with athletes from other sports, and hearing the din of cowbells as she rips around the course. But underneath all those COVID-induced changes, Diggins believes one thing will remain constant.

"Everyone is still excited,'' she said. "The Olympics lets us feel inspired. It lets us let go of all the stresses we're feeling in the moment. So despite everything happening in the world, we're excited to see what everyone can do.''