Unlike natural disasters, whose destruction is concentrated in a limited area over a period of days, and illnesses, which have devastating effects but are limited to individuals and their families, infectious disease has the terrifying power to disrupt everyday life on a global scale, overwhelming public and private resources and bringing trade and transportation to a grinding halt. In today's world, it's easier than ever to move people, animals, and materials around the planet, but the same advances that make modern infrastructure so efficient have made epidemics and even pandemics nearly inevitable. And as outbreaks of COVID-19, Ebola, MERS, and Zika have demonstrated, we are woefully under-prepared to deal with the fallout. So what can - and must - we do in order to protect ourselves from mankind's deadliest enemy?