In a cordoned-off section of the Beijing airport, arrivals for next month's Winter Olympics are met by staff in white protective suits and undergo COVID-19 tests and swabs of luggage before being whisked to fenced-off hotels in police-escorted buses.

Unlike last summer's Tokyo Games, which took place in a porous "bubble," the perimeters of Beijing's "closed loop" are sealed and guarded — precautions that will be put to the test as the highly transmissible omicron variant surges around the globe.

At the entrance to the Main Media Center this week, security personnel guarded a locked gate, police cars sat nearby and signs on temporary fences warned those within the area of the "end of the closed loop."