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Edward Jenner (1749-1823)
Smallpox took over from the bubonic plague as the major killer disease in the 18th century. Many died and those who survived were left severely disfigured or blind. Inoculation was used as a method for gaining immunity that involved spreading matter from a smallpox scab onto an open wound. This would result in a mild dose of the disease that would give immunity to any further attacks, this was first promoted by Lady Mary Wortley Montague. However, inoculation was not without risk as some people died from this mild dose or became carriers of the disease.
Who was Edward Jenner?
Edward Jenner worked as a doctor in the village of Berkeley in Gloucestershire. He found that when he tried to inoculate some of the local people they refused. This was because they believed that if they had suffered from a mild form of cowpox, a disease that affected cattle, they would be immune from catching smallpox.

What did Jenner discover?
By observing local milkmaids, Jenner tested whether the belief that cowpox sufferers were actually immune to smallpox was true. On 14th May 1796 he conducted an experiment by scraping pus from a cowpox sore on the arm of a milkmaid and inserting it into two cuts on the arm of a young boy. On 1st July 1796 he did exactly the same with pus from a smallpox sore. The boy caught cowpox, but did not catch smallpox. After conducting this experiment on 23 different cases he concluded that those who had suffered cowpox were indeed immune to smallpox. Jenner called this new method 'vaccination' which mean 'from a cow' as a way of distinguishing it from the process of 'inoculation'.

What medical changes did Jenner bring about?
In 1798 Jenner published his findings and submitted them to the Royal Society who refused to publish them because of opposition to vaccination from doctors. Doctors opposed vaccination because they were suspicious of new ideas and were accustomed to using inoculation. However, Jenner did have some support as members of the Royal Family were vaccinated and vaccination became widely accepted abroad. In 1802 he was awarded a grant of 10,000 by the government and then a further 20,000 in 1806. Vaccination became free for all infants in 1840 and became compulsory in Britain in 1853 and in 1980 the World Health Assembly declared that smallpox had been eradicated throughout the world.

Louis Pasteur (1822 - 1895)
For centuries doctors had tried to find out how disease was caused. In the mid-19th century, many people in Britain still believed in Miasma, the idea that disease was caused by polluted air. The real breakthrough in understanding the cause of disease was made not by a doctor, but a chemist called Louis Pasteur.
Who was Louis Pasteur?
Louis Pasteur was a French chemist working as a teacher in a university. He was asked by a wine company to explain why some wine turned sour whilst it was being made. Pasteur's research discovered that there were germs in the air that could cause liquids to go off.

What did he do next?
Having discovered that 'bad' wine had germs in it which could be seen through a microscope, Pasteur developed a process for killing the germs by boiling the wine and then cooling it down. He called this process 'pasteurisation'. Pasteur then set about proving that the germs came from the air and could therefore be prevented from entering the liquid in the first place. He demonstrated this by sealing a quantity of a liquid in an airtight jar and leaving another quantity exposed to the air. Pasteur now used his discovery to help treat diseases. He knew that the British doctor Edward Jenner had developed a process of vaccination against the killer disease, smallpox. Pasteur believed that his germ theory could be used to explain how vaccination worked. He examined the blood of healthy people and compared it with the blood of people with various diseases. He observed that when people were infected with disease their blood contained lots of germs.

What new ideas did Pasteur develop?
The process of boiling a liquid to destroy germs is still used today; most dairy products are pasteurised. Pasteur went on to discover vaccinations for chicken pox, cholera, diphtheria, anthrax and rabies. However, not all of Pasteur's ideas were accepted. He recommended that surgical instruments be boiled before an operation to kill any germs on them, but most surgeons ignored this advice. This had to wait until aseptic surgery developed in the 20th century.

How important was Pasteur?
Pasteur's work was revolutionary in discovering the link between germs and disease. This led the way for Robert Koch to later discover how each type of germ caused specific disease and who established a complete germ theory of disease

Robert Koch (1843-1910)
In the late 19th century two of the most dangerous killer diseases were cholera and tuberculosis. Cholera was nicknamed 'King Cholera' because no one seemed to be able to cure it. Tuberculosis was known as the 'White Death' because sufferers vomited up white matter as their lungs disintegrated. The man who made a breakthrough in the fight against these diseases was Robert Koch.
Who was Robert Koch?
Koch was a German scientist, born in Hanover in 1843. Koch read Louis Pasteur's work and in 1872 began research into the microbes affecting diseased animals and people.

What brought him to prominence?
In 1878 Koch discovered that microbes cause wounds to go septic, but his big breakthrough came when he decided to stain microbes with dye, enabling him to photograph them under a microscope. Using this method he was able to study them more effectively and prove that every disease was caused by a different germs. He identified the microbes that caused tuberculosis in 1882 and cholera in 1883.

How did he do this?
Koch's discoveries were the result of careful research and observation using the microscope, photography and dyes. As a result of his work, the German government also set up an 'Institute of Infectious Diseases' in Berlin in 1891 for medical research and development. These developments set the pattern for the future. In the 20th century medical research has increasingly involved teams of researchers supported by large public or private funds.

What did his research result in?
The scientific evidence of microbes helped reformers in public health prove that pollution spread disease. It meant certain kinds of action could be taken to prevent certain types of disease, since cholera was carried in water, for example, its spread could be prevented with clean water supplies.

What was his legacy?
Koch was responsible for establishing the new 'Science of Modern Bacteriology'. By 1900 he and his students had identified 21 germs causing diseases. Koch's assistant, Emil Behring, developed the first anti-toxin that could help to destroy the poison spread by bacteria in the blood stream. Koch's research on bacteria won him the Nobel Prize in 1905.


Alexander Fleming (1881-1955)
After Louis Pasteur's and Robert Koch's publications on the germ theory of disease, doctors developed a better understanding of the cause of infection. However, methods of treatment were still limited to vaccinations and anti-toxins. Joseph Lister's carbolic spray worked with some success during operations, but was not suitable for everyday use. The question was, how could people be protected against infection on a day to day basis?
What brought him to prominence?
Fleming was a farmer's son from Ayrshire in Scotland. He moved to London at 13 and later trained as a doctor. In 1928 Fleming was research assistant to Sir Almroth Wright working on bacteria. He accidentally discovered a mould on a set of culture dishes, which were being used to grow the staphylococci germ (which turns wounds septic). Fleming noticed that where there was mould the germs had stopped developing.

It was one of Fleming's colleagues who identified the mould as penicillin. Fleming subsequently tested the penicillin on animals, with no ill effects, and also used it to cure a colleague's eye infection.
How did Florey and Chain aid in this discovery?
After his initial discovery, Fleming did little more than keep a supply of the mould and return to his routine work. It was the scientists Howard Florey and Ernst Chain, who developed penicillin further. Florey and Chain were chiefly responsible for the research which led to its success as a drug, although Fleming took most of the credit for the discovery and its subsequent development.

How important was Fleming's discovery?
Fleming had discovered the first antibiotic. However, it was not until the research work of Florey and Chain that penicillin could be produced as a drug. At first supplies of penicillin were very limited, but by World War II it was being mass-produced by the American drugs industry, and given to all soldiers before active service.

Howard Florey (1898-1968) and Ernst Chain (1906-1979)
Alexander Fleming discovered pencillin in 1928 but did not fully realise the drug's potential. No further research was carried out due to lack of funds and specialist help. Howard Florey and Ernst Chain decided to develop Fleming's discovery further and set about finding a way to turn the pencillin mould juice into a pure drug, which would be more suitable for the treatment of humans.
Who were Howard Florey and Ernst Chain?
Florey was born in 1898 in Adelaide, Australia. He trained as a doctor and worked on a series of important discoveries at Oxford University. Chain a brilliant Jewish biochemist joined Florey's research team after he fled to Britain from Nazi Germany. Their development of penicillin in the early 1940s led to the award of the Nobel Prize alongside Fleming in 1945.

What are they famous for?
Chain was researching penicillin in 1929 when he read Fleming's article. It was this research which encouraged Florey and Chain to set up a fuller investigation into the drug. In 1940, Florey's team found a way of purifying penicillin which was tested first on mice and then on a patient, a policeman called Albert Alexander. The patient began to recover after receiving the drug, but unfortunately supplies ran out due to their inability to produce it in large quantites. Mass production of the drug was not possible without the help of large drugs companies.

What medical changes were brought about by their discovery?
Florey managed to persuade US drug companies to mass produce penicillin when the US entered the war in December 1941 because it could be used to treat infections caused by war wounds. The US government gave grants to drug companies who wanted to buy the expensive equipment needed to make penicillin. Mass production began in 1943 by British firms. By 1944 there was enough penicillin being produced to supply all the Allied armies. The price of penicillin fell and soon it was being used throughout the world to treat a range of different diseases.


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