Medical workers from Yunnan Province wave to bid farewell on the plane at Tianhe International Airport in Wuhan, central China's Hubei Province, March 18, 2020. (Xinhua/Fei Maohua)

Cured patients on a bus wave goodbye to medical workers in Wuhan, central China's Hubei Province, March 8, 2020. (Xinhua/Xiao Yijiu)

A staff member passes nucleic acid test kits at the plant of Luoyang Ascend Biotechnology Co., Ltd in Luoyang, central China's Henan Province, March 4, 2020. (Xinhua/Li Jianan)

An inbound passenger prepares to board a transfer vehicle at the transit center converted from the New China International Exhibition Center in Beijing, capital of China, March 17, 2020. (Xinhua/Peng Ziyang)

Photo taken on March 8, 2020 shows a closed makeshift hospital in Wuhan, central China's Hubei Province. (Xinhua/Xiao Yijiu)

Staff members prepare medical supplies to be delivered to Japan and South Korea at a customs warehouse in Shenyang, capital of northeast China's Liaoning Province, March 15, 2020. (Xinhua/Pan Yulong)

A staff member introduces an AI digital infrared thermometer at a building in Beijing, capital of China, March 16, 2020. (Xinhua/Ren Chao)