I was born in Germany and attended medical school in Dublin, Ireland. I completed a pediatric residency in Miami, an Infectious Disease Fellowship at UCLA and a PhD in epidemiology from the London School of Tropical Medicine and Hygiene. Between 1995 and 2000 I worked in The Gambia on the evaluation of antimalarial drugs in subSaharan Africa. From 2000 through 2006 I was employed by the International Vaccine Institute in Seoul, Korea where I managed large vaccine evaluation projects in Mozambique and Zanzibar. From 2006 I coordinated a trial of the malaria vaccine candidate RTS,S/AS01 in Tanzania. Since 2014 I have worked on malaria elimination, including the evaluation of malaria vaccine candidates at the Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand. We are currently assessing the impact of housing improvements on health in Tanzania. Since May 2020 I am collaborating with Chinese colleagues on the evaluation of COVID vaccine candidates.