1. Department of Immunology & Infection, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
2. Medicines for Malaria Venture, 20 rte de Pré Bois, Geneva CH 1215, Switzerland
3. Department of Clinical Parasitology, Hospital for Tropical Diseases, Mortimer Market Centre, Capper Street, London WC1E 6JB, UK