Development In the course of his work on lysozyme, Chain read papers on the enzyme in the
British Journal of Experimental Pathology by
Alexander Fleming in volumes 3 and 8, and by Florey in volume 11. While doing so he came across Fleming's paper discussing the antibacterial effects of
Penicillium notatum mould in volume 10. The erroneous impression given by Fleming that penicillin was a
bactericidal enzyme led Chain to consider that it would be similar to lysozyme. Money was short at the time; the office had an overdraft of £500 () and Florey had to forbid the purchase of any further equipment. Chain and Florey decided to create a large research project on antibacterial substances produced by micro-organisms that could attract long-term funding. Three sources were initially chosen for investigation:
Bacillus subtilis,
Trueperella pyogenes and
penicillin mould. Florey later said: Florey approached the MRC for funding in September 1939, shortly after the outbreak of the
Second World War, and Mellanby authorised the project, allocating £250 () to launch the project, with £300 for salaries and £100 for expenses per annum for three years. Florey felt that more would be required. On 1 November 1939, Henry M. "Dusty" Miller, Jr, from the Natural Sciences Division of the Rockefeller Foundation dropped by to discuss funding Heatley's position. Heatley had fallen out with Chain, and had accepted a new position at the
Carlsberg Laboratory in
Copenhagen on a Rockefeller Fellowship, but due to the outbreak of the
Second World War, he had decided to remain at Oxford. Miller arranged for Heatley to retain his fellowship. Instead of working for Chain, Heatley would report directly to Florey as his personal research assistant. commemorating the isolation and purification of penicillin at the
Sir William Dunn School of Pathology in Oxford As a bacteriologist, Miller was enthusiastic about the antibacterial project; he encouraged Florey to apply for a grant from the Rockefeller Foundation, and recommended to his headquarters that the request for financial support be given serious consideration. "The work proposed", Florey wrote in his application letter, "in addition to its theoretical importance, may have practical value for therapeutic purposes." Florey's application was approved, with the Rockefeller Foundation allocating US$5,000 (£1,250) per annum for five years. Florey's team already had a sample of penicillin mould; Dreyer had been given a sample of the mould in 1930 for his work on
bacteriophages. He had lost interest in penicillin when he discovered that it was not a bacteriophage, but Campbell-Renton had continued to cultivate it. The team developed techniques for growing the mould on a surface of liquid
Czapek-Dox medium. Most laboratory containers did not provide a large, flat area, so glass bottles laid on their sides were used. Later, specially-made containers were fabricated. As the laboratory gradually became a penicillin factory, Florey hired six women to perform the cultivation and extraction work. It had to be carried out under sterile conditions; Abraham and Chain discovered that some airborne bacteria produced
penicillinase, an enzyme that destroys penicillin. Heatley and Chain tackled the problem of how penicillin could be extracted from the mould. The liquid was filtered through parachute silk to remove the
mycelium,
spores and other solid debris. The
pH was lowered by the addition of
phosphoric acid and the liquid was then cooled. In this form the penicillin could be drawn off by a solvent. Initially
diethyl ether was used, but it is highly inflammable. At Chain's suggestion, they tried the much less flammable
amyl acetate, and found that it also worked. Penicillin-bearing solvent was easily separated, but now they encountered the problem that had stymied earlier attempts: recovering the penicillin from the solvent. Heatley reasoned that if the penicillin could pass from water to solvent when the solution was
acidic, maybe it would pass back again if the solution was
alkaline. Florey told him to give it a try. This method, which Heatley called "reverse extraction", was found to work. Chain hit upon the idea of
freeze drying to enable the water to be removed without damaging the penicillin. The team had thus developed a complete process for growing, extracting and purifying penicillin, resulting in a dry, brown powder. By early 1942, they could prepare a highly purified compound, and had proposed the chemical formula. Heatley developed an assay method. An Oxford unit was defined as the purity required to produce a 25 mm bacteria-free ring. It was an arbitrary measurement, as the chemistry of penicillin was not yet known; the first research was conducted with solutions containing four or five Oxford units per milligram. Later, highly pure penicillin became available with 2,000 Oxford units per milligram. to encourage further penicillin growth. The team discovered that
Penicillium extract killed several types of bacteria. Gardner and Orr-Ewing tested it against
gonococci (against which it was most effective),
meningococci,
streptococci,
staphylococci,
anthrax bacteria,
Actinomyces and the organisms that caused
tetanus and
gangrene. Florey and Jennings experimented on rats, mice, rabbits and cats in which penicillin was administered in various ways, and found no evidence of toxicity. On 25 May 1940, Florey injected eight mice with a virulent strain of
streptococcus, and then four of them with penicillin. A day later all four of the untreated mice were dead, but all of the treated ones were still alive, although one died two days later. Over the following weeks Jennings and Florey repeated the experiment with ever-larger batches of mice, and with different bacteria. They found that penicillin was also effective against
staphylococci and the bacteria that cause gangrene. They published their findings in
The Lancet on 24 August 1940. Florey reminded his staff that as promising as their results were, a man weighed 3,000 times as much as a mouse. In February 1941, Florey and Chain treated their first patient,
Albert Alexander, who had had a small sore at the corner of his mouth, which then spread, leading to a severe facial infection involving
streptococci and
staphylococci. His whole face, eyes and scalp were swollen to the extent that he had had an eye removed to relieve the pain. Within a day of being given penicillin, he started to recover. However, the researchers did not have enough penicillin to help him to a full recovery, and he relapsed and died. Because of this experience and the difficulty in producing sufficient penicillin, Florey switched his focus to children, who could be treated with smaller quantities of penicillin. Florey expected that penicillin would be hailed as a breakthrough, but he was disappointed; his results aroused little interest. He spent the next two years attempting to generate interest in what he believed to be the most important medical discovery of the century. He was elected a
Fellow of the Royal Society in March 1941, but his work with penicillin played little part in this.
North American supply As the war intensified with German air raids on the UK, Florey and Ethel decided to send their children away to a safer country in July 1940. The United States was not yet at war, and
John Fulton, the
Sterling Professor of
Physiology at
Yale University, and his wife Lucia agreed to care for them at their home in
New Haven, Connecticut, "for the duration". In April 1941, the Rockefeller Foundation's
Warren Weaver met with Florey, and they discussed the difficulty of producing sufficient penicillin to conduct clinical trials. Weaver arranged for the foundation to fund a three-month visit to the United States for Florey and a colleague so they could explore the possibility of the production of penicillin there. Since his aim was to persuade a firm to manufacture penicillin, and Heatley knew the most about penicillin production, Florey chose to take Heatley with him, and did not tell Chain until the morning of their departure. Chain, who saw penicillin as a joint project between himself and Florey, with Heatley as a laboratory technician, was greatly offended. Chain later wrote: "I left the room silently but shattered by the experience of this underhand trick and act of bad faith, the worst so far in my experience of Florey. It spoiled my initially good relations with this man for ever." Florey and Heatley left by air from Lisbon for the United States on 27 June 1941. In New Haven Florey met Fulton and was reunited with his children. Fulton introduced him to
Ross Harrison, the Chairman of the
National Research Council, and Harrison introduced him to
Charles Thom, the chief
mycologist at the
Bureau of Plant Industry of the
United States Department of Agriculture (USDA), and the man who had identified the mould reported by Fleming. Thom took them to
Washington, D.C., to see Percy Wells, the acting head of the USDA's four laboratories, and Wells sent them to Orville May, the director of the UDSA's
Northern Regional Research Laboratory (NRRL) in
Peoria, Illinois. May arranged for them to meet with Robert D. Coghill, the chief of the NRRL's
fermentation division, who raised the possibility that fermentation in large vessels (deep submergence) might be the key to large-scale production. On 17 August, Florey met with Richards, who had become the chairman of the Medical Research Committee of the
Office of Scientific Research and Development, who promised his support. Florey returned to Oxford in September without undertakings to produce the kilogram quantities of penicillin required for clinical trials, but the Japanese
attack on Pearl Harbor in December 1941 brought the United States into the war and infused a new urgency into penicillin production. Chain suggested applying for a
patent on the penicillin process. His motivation was not potential profits, but the danger of it being patented elsewhere. Florey took up the issue with Sir
Henry Dale, the chairman of the
Wellcome Trust and a member of the Scientific Advisory Panel to the
British Cabinet, and John William Trevan, the director of the Wellcome Trust Research Laboratory, but they were adamantly opposed, as they considered the notion of researchers profiting from their work as unethical. The Americans had no such scruples, and took out patents on the deep submergence processes they developed. Chain regarded Florey as naive for not patenting the penicillin production process.
Clinical trials In addition to the increased production at the Dunn School, commercial production from a
pilot plant established by
Imperial Chemical Industries became available in January 1942, and Kembel, Bishop and Company delivered its first batch of on 11 September. Florey conducted a second series of clinical trials. Ethel was placed in charge, but while Florey was a consulting pathologist at Oxford hospitals and therefore entitled to use their wards and services, Ethel, to his annoyance, was accredited merely as his assistant. Doctors tended to refer patients to the trial who were in desperate circumstances rather than those who were the most suitable candidates for treatment, but when penicillin did succeed anyway, confidence in its efficacy rose. Harry Lambert, a friend of Fleming's dying from a meningococcal infection, became the twelfth case on 5 August 1942. He survived, but someone at
St. Mary's Hospital leaked the result to the press, resulting in an editorial in
The Times on 27 August. Florey was appalled; this could only create a public demand for penicillin when all available supplies were needed for the clinical trials. On 25 September, Florey met with Sir Cecil McAlpine Weir, the Director-General of Equipment and Stores at the
Ministry of Supply, who promised overriding priority for the mass production of penicillin. Ethel and Howard Florey published the results of clinical trials of 187 cases of treatment with penicillin in
The Lancet on 27 March 1943.
North Africa The Medical Research Council decided that the time had come for field trials of penicillin. The location of centres to receive the drug was kept secret so as to not provoke demand for the drug when it was still in short supply. Florey was asked to go to North Africa, where the
North African campaign was ongoing. He travelled to
Algiers on the hospital ship in May 1943. On 29 June he was joined by
Hugh Cairns, another Rhodes Scholar from Adelaide, who now held the rank of
brigadier in the British Army, and was in charge of
St Hugh's Military Hospital (Head Injuries) in Oxford, who brought with him a stockpile of 40 million Oxford units of penicillin. Florey resisted well-intentioned efforts by the
War Office to grant him military rank. Over the next two months Florey and Cairns flew back and forth between Algiers,
Sousse and
Tripoli, with a week in
Cairo. They treated over one hundred cases and compiled a report that ran to over one hundred pages. He gave lectures on penicillin, and his report contained recommendations for training of medical officers in its use. The fighting in North Africa ended in May 1943, so most of the cases Florey saw were not recently wounded soldiers, but ones with old wounds that had not healed; battle casualties began arriving again after the
Allied invasion of Sicily in July. He considered that the source of infection in many cases was from the hospital rather than the battlefield, and advocated changes to the way that patients were treated to take advantage of the properties of penicillin. He argued that wounds should be cleaned and sealed up promptly. This was a radical idea; normally this would have been inviting
gas gangrene, but Florey proposed leaving that to the penicillin. His recommendations were acted upon, and the War Office established a training course for pathologists and clinicians at the
Royal Herbert Hospital, which made use of film that Florey shot in North Africa. Although he intended that penicillin be used to treat the seriously wounded, there were large numbers of
venereal disease cases, against which penicillin was particularly effective, and from a military point of view being able to cure
gonorrhea in 48 hours was a breakthrough. The supply situation improved, and 20 million units per day were made available for the
Allied invasion of Italy in September. Two out of three gas gangrene casualties now survived.
Soviet Union One result of the
Tehran Conference in November 1943 was an invitation for an Anglo-American scientific mission to visit the Soviet Union. The British team consisted of Florey and Sanders; the American of
Albert Baird Hastings and
Michael Boris Shimkin. After a month's travel via North Africa and Iran, they reached Moscow on 23 January 1944, where they met Soviet microbiologist
Zinaida Yermolyeva. Florey gave her samples of penicillin, and she gave him a sample of the antibiotic
Gramicidin S. He arrived back at Oxford on 29 March 1944.
Australia on arrival in Melbourne in 1944 In May 1944, the
Prime Minister,
John Curtin, and the Commander-in-Chief of the Australian Army,
General Sir
Thomas Blamey, visited London for the
1944 Commonwealth Prime Ministers' Conference. At Blamey's request, Curtin asked Florey if he would visit Australia as an advisor on the use of penicillin. Florey arrived in Australia in August 1944 to a hero's welcome, and he was awarded the degree of
Doctor of Medicine (MD) by the University of Adelaide. In accepting the degree, he recapitulated his own career, and spoke about the need to make it easier for research to be conducted in Australia. Florey met with Blamey; the two men got along well and chatted for several hours. It ended with Blamey convinced that Florey was the man to head a project Blamey had in mind: a medical research institute in
Canberra, the national capital. Blamey put his proposal to Curtin on 24 October. It was quickly approved, but Curtin became ill, and he died in July 1945. Florey discovered that penicillin production was already underway in Australia at the
Commonwealth Serum Laboratories (CSL) in Melbourne. In 1943, the
War Cabinet had agreed to produce penicillin in Australia, and Colonel
E. V. (Bill) Keogh, the Army's Director of Hygiene and Pathology, detailed Captain
Percival Bazeley and Lieutenant H. H. Kretchmar to establish a production facility. They visited Peoria, and obtained penicillin cultures from Coghill. The first Australian-made penicillin began reaching the troops in New Guinea in December 1943. Florey was full of praise for their achievement, but disturbed that they had turned to the Americans for advice instead of him. "Am I not Australian?" he asked Keogh, "Have I not had some leading role in this thing?"
Recognition Florey returned to the UK in October 1944, collecting his children from Fulton while en route. He was created a
Knight Bachelor on 8 June 1944, and
invested by King
George VI at
Buckingham Palace on 4 July 1944. He shared the
Nobel Prize in Physiology or Medicine in 1945 with Chain and Fleming. Fleming first observed the antibiotic properties of the mould that makes penicillin, but it was Chain and Florey who developed it into a useful treatment. Florey maintained that the penicillin project was originally driven by scientific interests, and that the medicinal discovery was a bonus. The neuroscientist
W. Maxwell Cowan observed that: Florey always insisted that the development of penicillin was a team effort and that he received more credit than he deserved, but the team itself was his creation. The philanthropist
Lord Nuffield offered Florey £50,000 () as a personal gift; Florey asked him instead to use it to establish research fellowships at the Sir William Dunn School. The first beneficiaries included Abraham, Heatley and Sanders. When the
Albert and Mary Lasker Foundation asked if it could reward him, as it had the staff at Peoria, he arranged for a commemorative rose garden with a memorial stone honouring Abraham, Chain, Fletcher, himself, Ethel Florey, Gardner, Jennings, Orr-Ewing and Sanders. ==Later life==