Nobel Prize in Physiology or Medicine 1945
Photo: Walter Stoneman. Nobel Foundation archive
Sir Alexander Fleming
Prize share: 1/3
Photo from the Nobel Foundation archive.
Ernst Boris Chain
Prize share: 1/3
Photo from the Nobel Foundation archive.
Sir Howard Walter Florey
Prize share: 1/3
The Nobel Prize in Physiology or Medicine 1945 was awarded jointly to Sir Alexander Fleming, Ernst Boris Chain and Sir Howard Walter Florey "for the discovery of penicillin and its curative effect in various infectious diseases"
Streams during Nobel Week
Watch the 2025 Nobel Prize lectures, Nobel Week Dialogue, the prize award ceremonies in Oslo and Stockholm and Nobel Peace Prize Forum here at nobelprize.org.
Explore prizes and laureates
Look for popular awards and laureates in different fields, and discover the history of the Nobel Prize.