Smallpox

Smallpox, caused by the variola virus, was a devastating disease which killed or disfigured most of its victims. Dating back to the third century BCE, spread of disease reached all areas of the world through spread of civilization. Highly contagious, this virus impacted historical events globally as smallpox infection led to the death of ruling leaders worldwide, decimated indigenous populations during exploration, and impacted battle outcomes as infection spread through troops. Variolation, the process of inoculating susceptible individuals with smallpox, resulted in a dramatic decline in smallpox deaths but still had a mortality rate of 2%. Edward Jenner’s smallpox vaccine, initially using cowpox virus, later using vaccinia virus, was a safer and more effective method of disease prevention. Collaborative international efforts implementing a mass immunization campaign, enhancing surveillance systems, and developing strategies of case findings and disease containment through isolation and vaccination led to global eradication of smallpox in 1980.