On This Day - July 26th 1978
The World Health Organisation announces that smallpox has been eradicated worldwide.
Smallpox is the only known major human disease to have been eradicated. It was a highly contagious viral disease unique to humans, caused by two virus variants called Variola major and Variola minor. V. major was the more deadly form, with a typical mortality of 20-40 percent of those infected. The other type, V. minor, only killed 1% of its victims. Smallpox was responsible for an estimated 300-500 million deaths in the 20th century. Survivors were left blind in one or both eyes from corneal ulcerations, and left with persistent skin scarring, or pockmarks.