History and Description of Vaccines and Herd Immunity

When discussing the history of vaccines, most people begin in 1796 with the invention of the direct predecessor to modern day vaccines.[1] However, the story actually “begins with the long history of infectious disease in humans, and in particular, with early uses of smallpox material to provide immunity to that disease.”[2] “Evidence exists that the Chinese employed smallpox inoculation (or variolation, as such use of smallpox material was called) as early as 1000 CE. It was practiced in Africa and Turkey as well, before it spread to Europe and the Americas.”[3]