Paul Griffiths MBE is Emeritus Professor of Virology at University College, London. His research concerns cytomegalovirus infection, where he helped to define the natural history and pathogenesis of this infection and used the information to design randomised controlled trials of antiviral drugs and prototype vaccines. His clinical laboratory at the Royal Free Hospital provided diagnosis of all viruses that infect humans. He served on the Joint Committee for Vaccination and Immunisation for 8 years and remains Chair of the Department of Health WHO committees on eradication of poliovirus and measles. He was the founding editor of Reviews in Medical Virology and is also Patron of the charity CMV Action.