Invisible Killers

The history and impact of influenza is explored, from its ability to constantly evolve to the constant threat it poses and the complex science behind it.

Smallpox causes an estimated 500 million deaths in the 20th century alone; experts fear the return of smallpox as a biological weapon.

Examining the 2014 Ebola outbreak, putting a spotlight on the slow global response that contributed to its status as the deadliest outbreak on record.