Short answers, pulled from the story.
Edward Jenner performed the first vaccination on James Phipps in 1796. He took pus from a milkmaid with cowpox and scratched it into the boy's arm to test immunity against smallpox.
Widespread vaccination campaigns led directly to the worldwide eradication of smallpox after the disease caused 763,094 cases in the United States alone in 1958. The World Health Organization declared the disease eradicated following these efforts.
Polio transmission restricts itself to parts of three countries: Afghanistan, Nigeria, and Pakistan. Sixty-three of sixty-four suspected cases in the country appeared in individuals who had never been vaccinated or were uncertain about their status by early 2008.
A ten-to-eleven-year study of 657,461 children found that the MMR vaccine did not cause autism. That same study showed the vaccine actually reduced autism risk by seven percent.
The European Medicines Agency reviews vaccine candidates scientifically alongside the US Food and Drug Administration during licensure phases One to Three. These phases demonstrate safety, immunoactivity, and proven effectiveness in target populations before approval.