1. Groupe de Recherche Action en Santé (GRAS), Ouagadougou 10248, Burkina Faso
2. Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita 565-0871, Osaka, Japan
3. European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115 Heidelberg, Germany
4. Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK