Fleming found penicillin, but it took two other scientists to make it a medicine

Alexander Fleming's 1928 discovery of penicillin sat largely unused for over a decade because no one could produce enough of it. Starting in 1939, Howard Florey and Ernst Chain's Oxford team worked out how to purify and mass-produce the mould's active compound, testing it on infected mice and then on desperately ill patients during WWII. Florey, Chain and Fleming shared the 1945 Nobel Prize for turning a laboratory curiosity into the first mass-produced antibiotic.

— The Nobel Prize Foundation, Howard Florey — Nobel Prize in Physiology or Medicine, 1945