A cured COVID-19 patient expresses her gratitude to health workers in Xi'an, northwest China's Shaanxi Province, Feb. 15, 2020. The patient was the first cured patient who was once in critical condition in Shaanxi Province. (Xinhua/Liu Xiao)

A cured COVID-19 patient (C) is discharged from the hospital in Xi'an, northwest China's Shaanxi Province, Feb. 15, 2020. The patient was the first cured patient who was once in critical condition in Shaanxi Province. (Xinhua/Liu Xiao)

A cured COVID-19 patient waves goodbye to a doctor after being discharged from the hospital in Xi'an, northwest China's Shaanxi Province, Feb. 15, 2020. The patient was the first cured patient who was once in critical condition in Shaanxi Province. (Xinhua/Liu Xiao)

A cured COVID-19 patient (R) expresses her gratitude to health workers in Xi'an, northwest China's Shaanxi Province, Feb. 15, 2020. The patient was the first cured patient who was once in critical condition in Shaanxi Province. (Xinhua/Liu Xiao)