To date, smallpox is the only major human disease that has been eradicated. September 11 happens to mark 40 years since Janet Parker became the last person ever to die from smallpox, and if you're interested, I thought I'd briefly share the story of this tragic milestone. 
Smallpox is a viral infection that has been around for millennia. It was characterized by a fever followed by an eruption of skin lesions that ranged from very mild to overwhelming and lethal. Ramses V, who died in 1156 BCE, is believed to be one of the earliest known cases.
Edward Jenner, an English physician, is credited with the discovery that inoculation with cowpox can protect against the closely related but far deadlier smallpox, and for over a century, this remained the basis for vaccination against smallpox.
In 1967, the @WHO launched an Intensified Smallpox Eradication Program combining mass vaccination and early containment of outbreaks. It was a great success; in 1977, Ali Maow Maalin of Somalia became the last person to contract smallpox naturally. He made a full recovery.
Henry Bedson was the chair of medical microbiology at Birmingham University and ran one of 2 labs in Britain studying smallpox. In May 1978, officials from the Dangerous Pathogens Advisory Group performed a site visit and determined that his lab did not meet safety requirements.
On August 6, Prof. Bedson received an official inspection report informing him that his laboratory would need to be upgraded to meet their standards and that if this was not done, he would need to halt his research as early as possible.
Janet Parker, was 40 years old and worked as a medical photographer for Birmingham University; her darkroom happened to be located directly above Prof. Bedson’s laboratory. She first fell ill on August 12, complaining of a headache and myalgias.
Ms. Parker initially dismissed her symptoms as a common cold, but within 2 weeks, she developed the telltale lesions and was admitted to a special isolation hospital with a diagnosis of smallpox, the first case in Britain in 5 years. The likely source was immediately apparent.
Within days after Prof. Bedson mailed his reply to the WHO informing them that the University did not have the funds for the necessary lab upgrades, he made a culture of material taken from Ms. Parker’s skin lesions. It was the same strain of smallpox Bedson had been studying.
While Prof. Bedson and his researchers had maintained their vacciations, Ms. Parker had not. As her condition deteriorated, Bedson’s became overwhelmed with guilt. On September 1, while his wife was distracted, he went to their garden and slit his throat; he died 5 days later.
Janet Parker's parents were observed under quarantine. On September 2, her father, Frederick Witcomb, was moved to the hospital for complaints of nausea. He died on September 5. He exhibited no signs of smallpox and is believed to have died of a heart attack.
Ms. Parker's mother, Hilda, did contract smallpox but survived. Ms. Parker, unfortunately, died of her illness on September 11. Birmingham University was ultimately cleared of blame, but her husband, Joseph, was given a payout of £26,500 over his wife's death.
Since 1984, all known samples of smallpox were destroyed except for those at two laboratories that have been authorized by WHO: the Centers for Disease Control and Prevention in the US and the State Research Center of Virology and Biotechnology in Koltsovo, Russia.
In 1986, the WHO recommended destruction of *all* remaining smallpox stocks, but due to continued resistance from some parties arguing that maintaining the smallpox may be useful for future research, this has been postponed numerous times and I believe it remains in limbo.
No long ago, there a HUGE twist in the smallpox story when govt employees discovered vials from the 1950s labelled "variola" in a seldom-used storage room in a @US_FDA lab in Bethesda. Tests later confirmed that the vials contained living smallpox virus! cnn.com/2014/07/11/hea…
The FDA smallpox vials were destroyed under WHO supervision in 2015, but the stores at the CDC and at the State Research Center of Virology and Biotechnology in Russia (and hopefully nowhere else) remain to this day.
