1. Section of Paediatrics, Division of Infectious Diseases
2. Section of Immunology, Division of Infectious Diseases, Imperial College
3. Department of Paediatric Infectious Diseases, Imperial College Healthcare NHS Trust
4. Immunobiology Unit, Institute of Child Health, University College London, London, UK
5. MRC Unit, The Gambia Vaccinology Theme, Fajara, The Gambia, West Africa