Fleming's discovery was not fully exploited until the outbreak of
the Second World War in 1939. Infected wounds had caused many deaths in previous wars and two researchers based in Oxford
University, Howard Florey and Ernst Chain, were given the task of finding new medicines to treat wounded soldiers.
They realised the importance of Fleming's work and had the resources to grow large amounts of the Penicillium mould.
This allowed them to isolate the active antibiotic in sufficient quantities to try it on patients suffering from severe infections.
Before antibiotics, a simple throat infection could easily spread to the lungs and throughout
the body. There was little that could be done for these patients and many died from complications of what we would now think
of as a trivial infection. Florey and Chain showed that Penicillin could be used to save lives.
The production of Penicillin became a wartime priority and pharmaceutical
factories in the USA, United Kingdom and Russia manufactured large quantities of Penicillin which was used to save the lives
of wounded soldiers.