Infection beyond doubt that certain diseases are caused by infectious agents, and developed a vaccine for rabies. Robert Koch, provided the study of infectious diseases with a scientific basis known as Koch's postulates. Edward Jenner, Jonas Salk and Albert Sabin developed effective vaccines for smallpox and polio, which would later result in the eradication and near-eradication of these diseases, respectively. Alexander Fleming discovered the world's first antibiotic, Penicillin, which Florey and Chain then developed. Gerhard Domagk developed sulphonamides, the first broad spectrum synthetic antibacterial drugs. The medical treatment of infectious diseases falls into the medical field of Infectious Disease and in
Jonas Salk of my first year of medical school, I received an opportunity to spend a year in research and teaching in biochemistry, which I did. And at the end of that year, I was told that I could, if I wished, switch and get a Ph.D. in biochemistry, but my preference was to stay with medicine. And, I believe that this is all linked to my original ambition, or desire, which was to be of some help to humankind, so to speak, in a larger sense than just on a one-to-one basis." Concerning his last year of medical school Salk says: