I am an epidemiologist and biostatistician working on the control of malaria and other infectious diseases. I trained initially in biology and ecology, followed by a PhD in population biology, and then a Wellcome Trust post-doctoral fellowship in biomathematics at the Liverpool School of Tropical Medicine helped me to switch focus to epidemiology and biostatistics. I worked as a statistician/epidemiologist at the MRC laboratories in The Gambia for 8 years, during which time I contributed to evaluation of the introduction of Hib conjugate vaccine showing its effectiveness, and to the first field trials showing the efficacy of the RTS,S vaccine. Since 2004 I have been based in the faculty of Epidemiology and Population Health in the London School of Hygiene&Tropical Medicine, where I teach statistics and epidemiology on our short courses and distance learning programmes, and I co-organise a distance learning MSc module on the epidemiology of infectious diseases. I have benefited from long term partnerships with researchers in the Universities of Cheikh Anta Diop and Thiès in Senegal, as well as with colleagues at LSHTM, on field studies of malaria control, and with the National University of Singapore, on statistical and epidemiological methods in infectious disease research, and with WHO. I led the public health evaluation of the scale-up of seasonal malaria chemoprevention in West Africa, showing its effectiveness, and I contributed to the large-scale evaluation of the introduction of the RTS,S vaccine in Ghana, Kenya and Malawi, which was recently completed, showing the vaccine’s impact in reducing mortality in young children, and I am involved in partnerships in West and Central Africa for implementation research to improve uptake and impact of malaria vaccines.