Smallpox is a highly contagious disease caused by the variola virus. It is characterized by fever, body aches, and a distinctive rash that develops into fluid-filled blisters. Historically, smallpox was responsible for significant mortality and morbidity, affecting millions of people worldwide. In 1980, the World Health Organization declared smallpox eradicated after a successful global vaccination campaign. This marked the first time a disease was completely eliminated through human effort. The smallpox vaccine, developed by Edward Jenner in the late 18th century, played a crucial role in this achievement, providing immunity and preventing the spread of the virus.