For 10,000 years, humanity suffered from the scourge of smallpox. The virus killed almost a third of its victims within two weeks and left survivors horribly scarred. But Simona Zompi commends the brave souls- a Buddhist nun, a boy, a cow, a dairymaid and physician Edward Jenner- who first stopped the spread of this disastrous disease, to make us smallpox-free today. [4:34]