Smallpox
Smallpox, the illness that has killed millions of people, was certified by the World Health Organization as eradicated in 1980. This is partly because, as the pandemic spread across all continents, scientists had managed to develop the first ever vaccine in an effort to stop it.
The origins of Smallpox are uncertain although we do have evidence of its existence as far back as 3rd century BCE, as it had been found in Egyptian mummies. Since then and up until 1980 there had been a series of outbreaks.
For example, one outbreak in the 18th century is said to have killed 400,000 Europeans per year. In the 20th century, estimates show that 200 million people died and in the last 100 years of the illnesses’ existence, it had killed 500 million people.
It was caused by two variants of the same virus, Variola major and Variola minor. The risk of death? 30%, with higher instances among children. In many cases, sufferers were left with extensive scarring, while others were left blind.
Edward Jenner was the British scientist who contributed to the discovery if the vaccine. Thanks to his efforts, along with the WHO, vaccines today are able to keep a number of illnesses at bay. He’s known for infecting his patients with cowpox, a far lesser illness, in order for their immune systems to ward off infections when they came in contact with the deadly strain of the virus at a later date.