A resident receives a nucleic acid test at a testing site in Longhua District of Haikou, south China's Hainan Province, Aug. 7, 2022. The Chinese mainland Saturday reported 337 locally-transmitted confirmed COVID-19 cases, of which 297 were in Hainan, the National Health Commission said Sunday. (Xinhua/Yang Guanyu)

A resident receives a nucleic acid test at a testing site in Longhua District of Haikou, south China's Hainan Province, Aug. 7, 2022. The Chinese mainland Saturday reported 337 locally-transmitted confirmed COVID-19 cases, of which 297 were in Hainan, the National Health Commission said Sunday. (Xinhua/Yang Guanyu)

A resident receives a nucleic acid test at a testing site in Longhua District of Haikou, south China's Hainan Province, Aug. 7, 2022. The Chinese mainland Saturday reported 337 locally-transmitted confirmed COVID-19 cases, of which 297 were in Hainan, the National Health Commission said Sunday. (Xinhua/Yang Guanyu)

A resident receives a nucleic acid test at a testing site in Longhua District of Haikou, south China's Hainan Province, Aug. 7, 2022. The Chinese mainland Saturday reported 337 locally-transmitted confirmed COVID-19 cases, of which 297 were in Hainan, the National Health Commission said Sunday. (Xinhua/Yang Guanyu)

A resident registers for a nucleic acid test at a testing site in Longhua District of Haikou, south China's Hainan Province, Aug. 7, 2022. The Chinese mainland Saturday reported 337 locally-transmitted confirmed COVID-19 cases, of which 297 were in Hainan, the National Health Commission said Sunday. (Xinhua/Yang Guanyu)