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.Seth Berkley explains how smart advances in vaccine design, production and distribution are bringing us closer than ever to eliminating a host of global threats -- from AIDS to malaria to flu pandemics.In our increasingly globalized world, a single infected person can board a plane and spread a virus across continents. Mark Honigsbaum describes the history of pandemics and how that knowledge can help halt future outbreaks.Bill Gates hopes to solve some of the world's biggest problems using a new kind of philanthropy. In a passionate and, yes, funny 18 minutes, he asks us to consider two big questions and how we might answer them. See it here.