David L. Heymann is currently Professor of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine and Head of the Centre on Global Health Security at Chatham House in London. Previously, he was WHO's Assistant Director-General for Health Security and Environment and before this he was Executive Director of the WHO Communicable Diseases Cluster where he led the global response to SARS. Before WHO, he was a medical epidemiologist in sub-Saharan Africa, on assignment from the US CDC where he participated in the first and second outbreaks of Ebola. In 2009 Prof Heymann was appointed an honorary Commander of the Most Excellent Order of the British Empire (CBE) for services to global public health.