Smallpox is an infectious disease caused by the variola virus. It is transmitted through inhalation of airborne droplets or contact with infected bodily fluids or contaminated objects. The incubation period is around 12 days. The clinical features progress from macules to papules, vesicles, pustules, and scabs. Treatment focuses on care of the skin and use of antibiotics to prevent complications. Strict isolation, disinfection, and active immunization were important preventive measures. The last known case of natural smallpox occurred in 1977, and it was declared eradicated by the WHO in 1980 due to successful vaccination programs.