1 Division of Respiratory Medicine and Stanley Ho Center for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, China.
2 Departments of Microbiology and Pediatrics, University of Iowa, Iowa City, IA, USA.
3 Division of Infection and Immunity, University College London, London NW3 2PF, UK; NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, London, UK. Electronic address: a.zumla@ucl.ac.uk.