1 Tsinghua University School of Medicine, Beijing 100084, China.
2 Pandemic Sciences Centre, University of Oxford, Oxford OX3 7LG, UK.
3 Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing 100029, China.
4 Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing 100029, China.
5 Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China.