The variola virus is the causative agent of smallpox, a highly contagious disease that was responsible for significant mortality throughout history. It belongs to the Poxviridae family and is characterized by its large, brick-shaped structure. Smallpox primarily spreads through respiratory droplets and direct contact with infected individuals or contaminated objects. 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 variola virus is now stored in secure laboratories for research purposes, as it poses a potential threat for bioterrorism.