This page discusses the renewed concerns regarding the use of biological agents, particularly the smallpox virus, in terrorism. Smallpox was eradicated in 1980 through effective vaccination and a lack...This page discusses the renewed concerns regarding the use of biological agents, particularly the smallpox virus, in terrorism. Smallpox was eradicated in 1980 through effective vaccination and a lack of animal reservoirs. Edward Jenner's pioneering vaccine using cowpox replaced the more dangerous variolation method.