An inquiry into the causes and effects of the variolae (or Cow-pox. 1798)

Few papers have had a greater impact on the health of the human species than the simple, yet elegant, observations and clinical trials of Edward Jenner with what was at the time called the Cow Pox. In fact, this was a naturally attenuated rodent (probably rat) pox that could infect horses and, through farriers and farm hands, dairy cattle. While commonly called the Cow Pox at the time, Jenner's transmission studies between humans used infectious materials from horses. His methods provided protection from the serious effects of smallpox infections. In 1977, smallpox was considered to be eradicated, although people continue to be infected by pox viruses from other mammalian species. We consider this to be our 'favorite historical paper' because it emphasizes careful clinical observation followed by relatively simple clinical testing can have a profound influence on human health, even when almost nothing is known about the underlying molecular mechanisms. Continued follow-up with strict attention to detail resulted in a crude but effective way to deal with an epidemic, methods still used today for containing infectious diseases.