Why has polio been so challenging to eradicate? Karen Torghele tells the story of two polio vaccines and the two rival scientists who developed them: Albert Sabin and Jonas Salk. Then, Dr. Ananda S Bandyopadhyay explains our best bet for eliminating the disease worldwide.

The Viral Universe Inside Us
30:29

Measles: The Cancer Killer?
29:40

Mosquitoes, Viruses and the History of the World
32:42