Medical workers scan the codes of nucleic acid samples at a testing lab in Sanya, south China's Hainan Province, Aug. 14, 2022. Sanya has optimized the processes of nucleic acid testing amid the latest COVID-19 resurgence. (Xinhua/Zhao Yingquan)

A medical worker transports nucleic acid samples at a testing lab in Sanya, south China's Hainan Province, Aug. 14, 2022. Sanya has optimized the processes of nucleic acid testing amid the latest COVID-19 resurgence. (Xinhua/Zhao Yingquan)

Medical workers scan the codes of nucleic acid samples at a testing lab in Sanya, south China's Hainan Province, Aug. 14, 2022. Sanya has optimized the processes of nucleic acid testing amid the latest COVID-19 resurgence. (Xinhua/Zhao Yingquan)

Volunteers transport nucleic acid samples in Sanya, south China's Hainan Province, Aug. 14, 2022. Sanya has optimized the processes of nucleic acid testing amid the latest COVID-19 resurgence. (Xinhua/Zhao Yingquan)