David Mabey is a physician specialising in Infectious and Tropical Diseases. After training in the UK he went to work at the Medical Research Council unit in The Gambia, West Africa in 1978, and was in charge of clinical services there from 1982-86. He became interested in trachoma while working in The Gambia, where it was an important cause of blindness, and where 3 trachoma vaccine trials had recently been completed. Unfortunately the vaccines were not protective, and his initial studies attempted to elucidate the protective and pathogenic immune responses to ocular Chlamydia trachomatis infection in humans. At that time the recommended treatment for trachoma was tetracycline ointment, applied twice daily to both eyes for 6 weeks. In the late 1980s a new antibiotic, azithromycin, became available, a single oral dose of which was sufficient to cure genital C. trachomatis infection. With his PhD student Robin Bailey, Mabey performed a randomised controlled trial in The Gambia which showed that a single oral dose of azithromycin was as good as 6 weeks of supervised tetracycline ointment in curing trachoma. However, reinfection was common when only individual cases were treated. With funding from the Edna McConnell Clark Foundation and collaborators in the USA, The Gambia, Egypt and Tanzania, he then took part in a multi-centre trial of community-based mass treatment with azithromycin, showing that it was highly effective and that treating the entire community reduced the rate of reinfection. As a result of this trial Dr Joe Cook of the McConnell Clark Foundation was able to persuade the manufacturer, Pfizer, to donate azithromycin for trachoma control, and in 1998 the World Health Assembly passed a resolution calling for the global elimination of trachoma as a public health problem by 2020. Mabey joined the London School of Hygiene & Tropical Medicine (LSHTM) as a Senior Lecturer in the Department of Clinical Sciences in 1986, and was made Professor of Communicable Diseases in 1994. He is an Honorary Consultant Physician at the Hospital for Tropical Diseases in London. He was head of the Clinical Research Unit at LSHTM from 1995-2002 and from 2017-2019, and was Director of the Wellcome Trust Bloomsbury Centre for Global Health Research from 1995 -2019. He currently chairs the Scientific and Technical Advisory Group of the WHO Department of Neglected Tropical Diseases, and was a member of the Scientific and Technical Advisory Group of the WHO Department of Reproductive Health and Research for 8 years. In 2011 he was awarded the George MacDonald Medal by the Royal Society of Tropical Medicine & Hygiene (RSTMH) in recognition of outstanding research leading to improvement of health in tropical countries), and in 2014 the Ronald Ross Medal by the RSTMH and LSHTM in recognition of outstanding contributions to research or other work in tropical public health or tropical medicine. He is currently president of the RSTMH, and was awarded a CBE by Her Majesty Queen Elizabeth in 2014 for services to health development in Africa and Asia.