1. Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia;
2. Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia;
3. Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark;
4. Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom;
5. Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia;
6. Centre for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland;
7. Microbiology and Infection Unit, Warwick Medical School, University of Warwick, Coventry, United Kingdom
8. Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom;