A History of Vaccination

Existing evidence shows that vaccination treatments go back over a thousand years ago. Considering the recent controversies surrounding vaccination policies and parental rights, it is often good to go backwards to understand a practice as a way to gain insight to the ways in which a society may approach the policies of the practice in the future.
Nova posted this beautifully illustrated history of vaccination.
http://video.pbs.org/viralplayer/2365317233