1 Division of Infection and Immunity, UCL Royal Free Campus, University College London, Rowland Hill Street, London NW3 2PF, UK; NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, London, UK. Electronic address: email@example.com.
2 Departments of Microbiology and Pediatrics, University of Iowa, IA, USA.
3 Rollins School of Public Health, Atlanta, GA, USA.
4 Public Health Practice, LLC, Atlanta, GA, USA.
5 London School of Hygiene and Tropical Medicine, London, UK.
6 Global Health Division, Public Health England, London, UK.
7 Division of Respiratory Medicine and Stanley Ho Center for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, New Territories, Hong Kong.