1. Intensive Care Unit, Royal Free Hospital, Royal Free London NHS Foundation Trust, London, UK
2. HIV Services, Royal Free Hospital, Royal Free London NHS Foundation Trust, London, UK
3. Centre for Clinical Research, Epidemiology, Modelling and Evaluation, Institute for Global Health, University College London, London, UK
4. UCL Respiratory, Division of Medicine, University College London, London, UK
5. Respiratory Medicine, Royal Free Hospital, Royal Free London NHS Foundation Trust, London, UK
6. National Institute for Health and Care Research (NIHR) Health Protection Research Unit in Blood Borne and Sexually Transmitted Infections, University College London, London, UK
7. Centre for Clinical Research in Infection and Sexual Health, Institute for Global Health, University College London, London, UK