Abstract
Vaccine history is inextricably linked with the histories of microbiology and immunology; evolution of the latter disciplines parallels the ongoing quest of humankind to understand the fundamental basis of life. How our species survives in the hostile world that surrounds us has been a source of fascination since the beginning of recorded time. Injury and infection likely exacted a heavy toll as our early hominid ancestors descended from the trees and adapted a predatory life style on the African plains; death from bleeding and wound infections undoubtedly plagued early humans (Opal 2003). Epidemic disease, however, probably played a minor role in shaping the primitive human immune system. Instead, the primary determinants of lethality for small, scattered bands of hunter-gatherer populations of Homo sapiens were starvation, predation, and hypothermia.