Health workers (L-R) Bai Hui, Li Chunfang, Zhao Zhigang and Guo Qin, who have recovered from recent novel coronavirus infections, pose for a group photo at the emergency medical center of Zhongnan Hospital of Wuhan University in Wuhan, central China's Hubei Province, Feb. 6, 2020. The four had been infected with the novel coronavirus during work. They will return to the healthcare frontline to continue battling the novel coronavirus epidemic. (Photo by Gong Yong/Xinhua)