Jenner was an English doctor who developed that first Smallpox vaccine. Having heard the claim that milkmaids cannot catch smallpox after already being infected with the less serious cowpox, he intended to test this theory. In 1796, Jenner took a sample of cowpox pus from a milkmaid, Sarah Nelmes and placed in into a incision on a young boy, James Phipps arm. Next, he gave James a sample of smallpox and the boy did not become ill. In 1853, a law was introduced that made the vaccine compulsory for all newborns and in 1980, smallpox had been eradicated. There was opposition to the vaccine as many Christians saw it as going against God's will, or the idea of being intentionally given an animal disease was seemingly unsafe.