John Patrick Vaughan was a multidisciplinary epidemiologist and Emeritus Professor of Epidemiology and Public Health at the London School of Hygiene and Tropical Medicine (LSHTM). He was born on December 27, 1937 in Penzance, United Kingdom and died on July 26, 2025 in London at the age of 87 of acute myeloid leukemia. After gaining a diploma in tropical public health in 1969 and a doctorate in medicine in 1978, he worked at LSHTM from 1975. He headed the MRC Tropical Epidemiology Unit and founded the Evaluation and Planning Center in 1979. He worked in various countries including Papua New Guinea, Tanzania, Bangladesh and collaborated with the WHO, the World Bank and the British NHS. He was the founder and first editor of the journal Health Policy and Planning, which focuses on health policy and systems in developing countries. Throughout his career, he has published numerous scientific papers and books, including an updated edition of Practical Epidemiology in 2021, which reflected the experience of the COVID-19 pandemic. He was a recognized mentor and made significant contributions to the development of global public health and epidemiology[1][2][3][7].