1. Department of Respiratory Medicine; Zhujiang Hospital; Southern Medical University; Guangzhou People's Republic of China
2. Nanfang Hospital; First Clinical Medical College; Southern Medical University; Guangzhou People's Republic of China
3. Department of Respiratory Diseases; Sun Yat-sen Memorial Hospital; Sun Yat-sen University; Guangzhou People's Republic of China
4. Biosafety Level-3 Laboratory; School of Public Health and Tropical Medicine; Southern Medical University; Guangzhou People's Republic of China