He has previously held positions as International Research Fellow at the National Centre for Immunisation Research in Sydney, Consultant Epidemiologist with the UK Health Protection Agency and WHO focal point for Communicable Disease Surveillance and Response in the Vietnam Country Office. Since February, 2006, he has been Director of the Oxford University Clinical Research Unit at the National Institute of Infectious and Tropical Diseases, Hanoi, Vietnam. He has experience of a range of emerging infections including variant Creutzfeldt-Jakob disease, SARS, and avian influenza.