CLEP Western Civ II

Answer: D - Edward Jenner created the first successful smallpox vaccine. He realized that milkmaids did not get smallpox and concluded that this was because of their exposure to cowpox, a variation of the strain. While they did develop sores from the cowpox, these were minimal compared to the devastation that smallpox caused. This observation enabled him to create a vaccine, and the process of vaccination spread globally in the 19th century. Smallpox would become the first disease eliminated through inoculation.