The last cases of smallpox in the world occurred in an outbreak of two cases (one of which was fatal) in Birmingham, UK in 1978. A medical photographer, Janet Parker, contracted the disease at the University of Birmingham Medical School and died on September 11, 1978, after which the scientist responsible for smallpox research at the university, Professor Henry Bedson, committed suicide. In light of this incident, all known stocks of smallpox were destroyed or transferred to one of two WHO reference laboratories which had BSL-4 facilities; the Centers for Disease Control and Prevention (CDC) in the United States and the State Research Center of Virology and Biotechnology VECTOR in Koltsovo, Russia.
In 1986, the World Health Organization first recommended destruction of the virus, and later set the date of destruction to be 30 December 1993. This was postponed to 30 June 1999. Due to resistance from the US and Russia, in 2002 the World Health Assembly agreed to permit the temporary retention of the virus stocks for specific research purposes. Destroying existing stocks would reduce the risk involved with ongoing smallpox research; the stocks are not needed to respond to a smallpox outbreak. Some scientists have argued that the stocks may be useful in developing new vaccines, antiviral drugs, and diagnostic tests, however, a 2010 review by a team of public health experts appointed by the World Health Organization concluded that no essential public health purpose is served by the US and Russia continuing to retain virus stocks. The latter view is frequently supported in the scientific community, particularly among veterans of the WHO Smallpox Eradication Program.
In March 2004 smallpox scabs were found tucked inside an envelope in a book on Civil War medicine in Santa Fe, New Mexico. The envelope was labeled as containing scabs from a vaccination and gave scientists at the Centers for Disease Control and Prevention an opportunity to study the history of smallpox vaccination in the US.