In the early 1800s, a scientist named Edward Jenner discovered a way to prevent humans from getting smallpox by injecting them with a similar disease found in animals. Later, Louis Pasteur discovered that microorganisms caused diseases. He combined Jenner’s work with his own discovery to create the first vaccine.
Pasteur chose to focus on a rabies vaccine because it was big problem. In the 1800’s rabies was prevalent in both the US and Europe. He also liked that he could experiment on animals, but apply the results to humans. He was able to create a preventative vaccination for dogs, and a post-bite treatment for humans. By 1886, he had successfully vaccinated 349 people. He shared this information