David is Professor of Infectious Disease Epidemiology at LSHTM and former Head of the Centre on Global Health Security at Chatham House, London. From 2012 to 2017 he was chairman of Public Health England. David is an elected fellow of the Institute of Medicine of the National Academies (US) and the Academy of Medical Sciences (UK), and has received seven different public health awards.

David has held numerous positions at WHO, including Executive Director of the Communicable Diseases Cluster, leading the global response to SARS, and Assistant Director for Health Security. Before joining WHO, David was based in sub-Saharan Africa and India, responding to outbreaks of Ebola, smallpox and supporting research to control infectious diseases.