1. From the Kenyan Medical Research Institute (KEMRI) Centre for Geographic Medicine Research (coast), Kilifi, Kenya (PB, SM, IM, SHA, FO, NP, KM, CRN, and JAB); the Nuffield Department of Medicine, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, United Kingdom, (PB, SHA, and JAB); the Department of Paediatrics and Wellcome Trust Centre for Cl