10 million cases and 2 million deaths were occurring annually. Vaccination brought some control, but the key strategy was "surveillance-containment". This technique entailed rapid reporting of cases from all health units and prompt vaccination of household members and close contacts of confirmed cases. WHO staff and advisors from some 73 countries worked closely with national staff. The last case occurred in Somalia on October 26, 1977, only 10 years after the program began. Three years later, the World Health Assembly recommended that smallpox vaccination could cease. Smallpox is the first human disease ever to be eradicated. This success gave impetus to WHO's global Expanded Program on Immunization, which targeted other vaccine-preventable diseases, including poliomyelitis, measles, tetanus, diphtheria, and whooping cough. Now targeted for eradication are poliomyelitis and Guinea Worm disease; after 25 years, this objective is close to being achieved. Later work From 1977 through August 1990, Henderson was Dean of the Johns Hopkins School of Public Health. After being awarded the 1986 National Medal of Science by Ronald Reagan for his work leading the World Health Organization (WHO) smallpox eradication campaign, Henderson launched a public struggle to reverse the Reagan administration’s decision to default on WHO payments. In 1991, he was appointed associate director for life sciences, Office of Science and Technology Policy, Executive Office of the President (1991–93) and, later, deputy assistant secretary and senior science advisor in the Department of Health and Human Services (HHS). In 1998, he became the founding director of the Johns Hopkins Center for Civilian Biodefense Strategies, now the Johns Hopkins Center for Health Security. Following the September 11, 2001, attack on the World Trade Center, HHS Secretary Tommy G. Thompson asked Henderson to assume responsibility for the Office of Public Health Preparedness (later the Office of the Assistant Secretary for Preparedness and Response). For this purpose, $3 billion was appropriated by Congress. In 2006, Henderson published an academic paper critical of social distancing as a pandemic measure, saying it would "result in significant disruption of the social functioning of communities and result in possibly serious economic problems". At the time of his death, he served as the Editor Emeritus of the academic journal Health Security (formerly Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science). Honors and awards 1975 – George McDonald Medal, London School of Tropical Medicine 1978 – Public Welfare Medal, National Academy of Sciences 1985 – Albert Schweitzer International Prize