Humans have had to deal with infectious diseases for centuries. Ancient Greeks and Egyptians suffered from smallpox, leprosy and tuberculosis. And when an outbreak occurs, it can be devastating.
While improved sanitation and a better understanding of how infections spread has helped halt some pandemics, we are never truly safe. Recent outbreaks of Ebola in Western Africa and the Zika virus in the Americas show how vulnerable we are.
William Isdale speaks with Melbourne University Professor and Nobel prize winner Peter Doherty about how infectious diseases start and spread, and what can be done by governments, health organisations and individuals to minimise the threat of a pandemic.