1. Institute for Global Health, University College London, 30 Guilford Street, London, WC1N 1EH, England.
2. Great Ormond Street Institute of Child Health, University College London, London, England.
3. Institute for Women's Health, University College London, London, England.
4. Clinical Operational Research Unit, University College London, London, England.
5. School of Management, University College London, London, England.
6. Centre for Infectious Disease Epidemiology, University College London, London, England.
7. Department of Primary Care and Population Health, University College London, London, England.