Edward Jenner is a physician who introduced the smallpox vaccine in 1796 ("Edward Jenner"). Jenner vaccinated a boy with the vaccine and found that the boy did not contract the disease ("Edward Jenner"). This brought the British government to decide on banning variolation in 1840 and replace it with free smallpox vaccination ("Edward Jenner"). In 1979, the World Health Organization declared that smallpox had been completely effaced thanks to the vaccine (Scott).
Jenner studied angina pectoris, ophthalmia, valvular disease, and cowpox. He wrote about his findings and contributed his papers to the scientific community ("Edward Jenner").
How does this affect me?
Without the smallpox vaccine, I would be living in a world where smallpox would still be an epidemic. I would have people around me suffering from the disease and probably myself as well. Thanks to vaccine, smallpox is no longer a global problem.
(image from http://en.wikipedia.org/wiki/Image:Edward_Jenner2.jpg)