FILE - A staff member stands near a sign outlining COVID-19 protection measures during the Experience Beijing Ice Hockey Domestic Test Activity, a test event for the 2022 Beijing Winter Olympics, at the National Indoor Stadium in Beijing, on Nov. 10, 2021. The prevention protocols will be similar to those at the Tokyo Games this summer, but tighter. It won't be a stretch for Beijing organizers, with China having maintained its zero-tolerance policy to the virus nationally since early in the pandemic. (AP Photo/Mark Schiefelbein, File)

A woman wearing a face mask to protect against COVID-19 walks past a clock counting down the time until the opening ceremony of the 2022 Winter Olympics in Beijing, Saturday, Jan. 15, 2022. As the Beijing Winter Olympics loom, the Chinese capital is stepping measures to keep the coronavirus at bay including suspending most access to Tianjin, an adjacent major city which is dealing with an outbreak of the highly contagious omicron variant. These outbreaks are posing a test to its "zero-tolerance" COVID-19 policy and its ability to successfully host the Winter Olympics. (AP Photo/Mark Schiefelbein)