The World Health Organization estimates that two-thirds of the 5 million child deaths in developing countries each year are directly caused by infectious diseases such as pneumonia, diarrhea and malaria and that undernutrition contributes to nearly half of child deaths. Robert E. Black, M.D., M.P.H. has focused his research and professional activities on reducing the number of these unnecessary deaths. He is conducting epidemiologic research on the interaction of infectious diseases and nutrition, clinical and community-based trials of new vaccines to prevent childhood infectious diseases, and trials of nutritional interventions to reduce infectious disease morbidity and mortality, as well as improve growth and development. He is also assisting with implementation of disease control and nutrition programs in developing countries and conducting evaluations of their effectiveness and mortality impact. His other interests are related to the use of evidence in policy and programs, estimation of the burden of disease, development of research capacity and strengthening of public health training.