World Health Organization Intensifies Its Campaign to Eradicate Smallpox.

Smallpox, or variola, plagued humanity as one of the world’s major epidemic diseases for about three thousand years. Without an effective, disease-specific treatment for the infection, up to 25 percent of individuals affected by variola major, the deadlier form of the smallpox virus, succumbed to the infection. Survivors acquired lifelong immunity and were easily recognized by the disfiguring pockmarks on their faces.