The 1978 smallpox outbreak in the United Kingdom resulted in the death of Janet Parker, a British medical photographer, who became the last recorded person to die from smallpox. Her illness and death, which was connected to the deaths of two other people, led to the Shooter Inquiry, an official investigation by government-appointed experts triggering radical changes in how dangerous pathogens were studied in the UK. The Shooter Inquiry found that Parker was accidentally exposed to a strain of smallpox virus that had been grown in a research laboratory on the floor below her workplace at the University of Birmingham Medical School. Shooter concluded that the mode of transmission was most likely airborne through a poorly maintained service duct between the two floors. However, this assertion has been subsequently challenged, including when the University of Birmingham was acquitted following a prosecution for breach of Health and Safety legislation connected with Parker's death. Several internationally recognised experts produced evidence during the prosecution to show that it was unlikely that Parker was infected by airborne transmission in this way. Although there is general agreement that the source of Parker's infection was the smallpox virus grown at the Medical School laboratory, how Parker contracted the disease remains unknown. Background Smallpox research at the Birmingham Medical School Smallpox is an infectious disease unique to humans, caused by either of two virus variants named Variola major and Variola minor. The World Health Organization (WHO) had established a smallpox eradication programme and, by 1978, was close to declaring that the disease had been eradicated globally. The last naturally occurring infection was of Variola minor in Somalia in 1977. At the time of the 1978 outbreak, a laboratory at University of Birmingham Medical School had been conducting research on variants of smallpox virus known as "whitepox viruses", which were considered to be a threat to the success of the WHO's eradication programme. The laboratory was part of the Microbiology Department, the head of which was virologist Henry Bedson, son of Sir Samuel Phillips Bedson. A smallpox outbreak in the area had occurred in 1966, when Tony McLennan, a medical photographer working at the medical school, contracted the disease. He had a mild form of the disease, which was not diagnosed for eight weeks. He was not quarantined and there were at least twelve further cases in the West Midlands, five of whom were quarantined in Witton Isolation