Dr. D. A. Henderson explains how a $200 prize in 1950 changed his career path from cardiology to public health.

What Dr. Henderson doesn’t say is that his decision not only changed his life, but ultimately changed the course of history. From 1967-1977 Dr. Henderson led the World Health Organization effort to eradicate smallpox.

Smallpox infected more than a billion people in the 20th century, killing more than 300 million; however, there has not been a single infection or death from smallpox since it was officially declared eradicated by WHO in 1980.