The history of smallpox vaccination goes back thousands of years to ancient China where a practice of blowing powder from pulverized smallpox scabs into the nostrils was used as a means of inoculation. In the 1790’s, Edward Jenner, a British surgeon noticed that dairymaids who developed cowpox (a mild infection from milking cows) rarely caught smallpox. Jenner took matter from active cowpox lesions on the hands of a young dairymaid and inoculated an 8-year old boy named James Phipps. The boy developed a mild illness, recovered and was later inoculated with matter from a fresh smallpox lesion. He did not develop smallpox. Learn more on this story by watching the TED Ed lesson: How we conquered the deadly smallpox virus. This process evolved over the following centuries to the use of the bifurcated needle, an innovation with large implications for use in smallpox vaccination campaigns. The Smallpox Eradication Program represents one of the greatest public health achievements in history.

In 1988, the World Health Assembly adopted a resolution for the worldwide eradication of poliomyelitis. Since the launch of the Global Polio Eradication Initiative, only three countries remain that have never interrupted transmission of polio - Nigeria, Afghanistan and Pakistan. Two different vaccines, oral polio vaccine (OPV) and inactivated polio vaccine (IPV) have been instrumental in achieving a 99% reduction in polio cases worldwide. The end stages of eradication will involve a globally coordinated effort involving these two vaccines to that ensure all polioviruses are permanently eradicated. A self-directed, animated presentation of this process can be viewed here.

Visit the World Health Organization (WHO) website and find out more about Guinea Worm disease. More information about the Guinea Worm Eradication Program can be found here. How many cases of Guinea Worm disease were there in 2014? Download the Guinea worm: Countdown to Zero App and follow along.