University College London, University College London, University College London, Kalawati Saran Children's Hospital, - Department of Pediatrics, University of Cape Town (UCT) - Division of Clinical Pharmacology, University of Zimbabwe Faculty of Medicine and Health Sciences, MU-JHU Care Ltd - MUJHU Research Collaboration, Pham Ngoc Thach Hospital, University of York, Lady Hardinge Medical College, Post Graduate Institute of Medical Education & Research (PGIMER), University Teaching Hospital, University of Zimbabwe - Clinical Trials Research Centre, Hanoi Medical University - Vietnam National Lung HospitalHanoi Medical University - Vietnam National Lung Hospital, University College London, Radboud University Nijmegen - Radboud University Medical Center, University Teaching Hospital, Lady Hardinge Medical College and Kalawati Saran Children's Hospital, affiliation not provided to SSRN, University College London, affiliation not provided to SSRN, University College London - MRC Clinical Trials Unit, Imperial College London, Hospital of Tropical Diseases - Oxford University Clinical Research Unit, University of Oxford - Nuffield Department of Medicine, University College London and University College London - MRC Clinical Trials Unit