Detailed text transcripts for TV channel - CNN - 20110516:17:41:00
Caused by a virus and also responsible for up to half a billion deaths in the last century alone. many smallpox patients who did survive were either severely scarred or blind because of the infection. this doctor knows well how bad this disease is. he led the world war effort to stamp it out. >> it's been the worst disease known to mankind. plague, cholera, all of -- yellow fever, all of these are really minor problems compared to smallpox. >> reporter: there hasn't been a case of smallpox in more than three decades. we don't routinely vaccinate for this anymore. but there are two places in th...