smallpox science definition

A highly infectious and often fatal disease caused by the variola virus of the genus Orthopoxvirus and characterized by fever, headache, and severely inflamed skin sores that result in extensive scarring. Once a dreaded killer of children that caused the deaths of millions of Native Americans after the arrival of European settlers in the Americas, smallpox was declared eradicated in 1980 following a worldwide vaccination campaign. Samples of the virus have been preserved in laboratories in the United States and Russia. Also called variola. See Note at Jenner.