Passengers at Pudong International Airport in Shanghai
FILE - Passengers wearing face masks to help protect against the coronavirus take rest at Pudong International Airport in Shanghai, China on July 25, 2021. Delta Air Lines said Monday, Dec. 27, 2021, that new cleaning requirements at a Shanghai airport were behind the decision to turn back a recent flight from Seattle in mid-air, a move that had prompted a protest from the Chinese consulate in San Francisco. (AP Photo/Andy Wong, File)
