In this photo released by China’s Xinhua News Agency, a worker wearing a protective suit collects a throat swab sample at a COVID-19 testing site in Xi’an in northwestern China’s Shaanxi Province, Tuesday, Dec. 21, 2021. China on Wednesday ordered millions of people locked down in neighborhoods and workplaces in the northern city of Xi’an following a spike in coronavirus cases. (Li Yibo/Xinhua via AP)