Donald Ainslie Henderson (September 7, 1928 – August 19, 2016) was an American medical doctor, educator, and epidemiologist who directed a 10-year international effort (1967–1977) that eradicated smallpox throughout the world and launched international childhood vaccination programs. From 1977 to 1990, he was Dean of the Johns Hopkins School of Public Health. Later, he played a leading role in instigating national programs for public health preparedness and response following biological attacks and national disasters. At the time of his death, he was Professor and Dean Emeritus of the Johns Hopkins Bloomberg School of Public Health, and Professor of Medicine and Public Health at the University of Pittsburgh, as well as Distinguished Scholar at the UPMC Center for Health Security. Early life and education Henderson was born in Lakewood, Ohio, on September 7, 1928, of Scots-Canadian immigrant parents. His father, David Henderson, was an engineer; his mother, Eleanor McMillan, was a nurse. His interest in medicine was inspired by a Canadian uncle, William McMillan, who was a general practitioner and senior member of the Canadian House of Commons. Henderson graduated from Oberlin College in 1950 and received his MD from the University of Rochester School of Medicine in 1954. He was a resident physician in medicine at the Mary Imogene Bassett Hospital in Cooperstown, New York, and, later, a Public Health Service Officer in the Epidemic Intelligence Service of the Communicable Disease Center (now the Centers for Disease Control and Prevention—CDC). He earned an MPH degree in 1960 from the Johns Hopkins School of Hygiene and Public Health (now the Johns Hopkins Bloomberg School of Public Health). Research and career Eradication of smallpox Henderson served as Chief of the CDC virus diseaser surveillance programs from 1960 to 1965, working closely with epidemiologist Alexander Langmuir. During this period, he and his unit developed a proposal for a United States Agency for International Development (USAID) program to eliminate smallpox and control measles during a 5-year period in 18 contiguous countries in western and central Africa. This project was funded by USAID, with field operations beginning in 1967. The USAID initiative provided an important impetus to a World Health Organization (WHO) program to eradicate smallpox throughout the world within a 10-year period. In 1966, Henderson moved to Geneva to become director of the campaign. At that time, smallpox was occurring widely throughout Brazil and in 30 countries in Africa and South Asia. More than