This month marks the 200th birthday of Louis Pasteur. The pioneering French scientist made major discoveries in microbiology. He was one of the first scientists to prove that microbes can make people sick. He also developed pasteurization, a process that uses heat to kill the germs in food. Today this method is widely used to ensure things like milk and canned food are safe to eat and drink.

Pasteur is best known for creating vaccines that protected people from contracting deadly diseases. “Vaccines contributed to a dramatic increase in the life expectancy of human beings,” says Maxime Schwartz, a former director of the Institut Pasteur in France. The organization continues to conduct biomedical research in Pasteur’s honor.