The vaccine for small pox was discovered by _______________.

The vaccine for small pox was discovered by Edward Jenner.
An English physician named Edward Jenner observed that many milkmaids who contracted cowpox, a disease in cows that causes only mild illness in humans, either did not contract smallpox or had milder disease and lower mortality. In 1796, he experimented by taking the fluid from a cowpox blister on a milkmaid’s hand and administering it to a young boy through incisions on his arm. Jenner discovered that exposing the boy to the cowpox virus protected him from smallpox. This experiment was the first scientific attempt to control an infectious disease through vaccination.