A brief history of Vaccine developement

October 3, 2008 by dadmin

The concept that individuals who survive an infectious disease do not get infected a second time is as old as humankind. Thucydides recorded that in the Peloponnesian War (431 BC) survivors of the plague took care of the sick believing they would not get the disease again. We now know that this is due to our immune systems which recognize invading materials as foreign and organizes a defense against them. Although it has to be admitted that not all of the details are clearly defined even today. Pliny the Elder reported in his encyclopedia of natural science that the Romans explored the use of the divers from dogs who had died from rabies in order to prevent the disease in man but this effort remains an antique curiosity.

Although two centuries have gone by since the investigations by Jenner in the 1790s into Vaccinia that began the modern phase of vaccine development, vaccination as such can be traced back much earlier. Around 1716 Lady Mary Pierrepont, wife of the then British Ambassador to the Turkish Porte or Court in Istanbul, Sir Edward Wortley Montagu, and herself scarred from an earlier attack of smallpox, reported that Turkish village women
exposed healthy individuals to scabs and pustules obtained from patients who manifested mild cases of the disease.

Two points need to be made from this observation, namely that the disease can vary in intensity from patient to patient and that immunity can be transferred. Since she had also lost a brother to the disease she reported this observation in letters home and, when she eventually arrived back in London, she introduced the practice to society and had her own children successfully vaccinated. It might be worth pointing out here that the Turkish practice probably originated in China centuries prior to this observation. Effectively what these ancients had discovered was the variability of the intensity of the infection (virulence), a key issue in the development of a safe vaccine.

Toward the end of the 18th century Edward Jenner, a country doctor, and coincidentally already vaccinated against smallpox by the then fashionable process introduced by Lady Pierrepont, had noted that there was a legend amongst country people that milk maids suffered a mild form of smallpox called cowpox that was nonfatal and did not leave the debilitating scars associated with smallpox itself. To his eternal credit Jenner decided to investigate this phenomenon and discovered that the legend was true. Cowpox protected against the more virulent smallpox and could be used as a vaccine. At the time the British medical establishment mocked these findings, but doctors across Europe followed through and confirmed that cowpox made an effective and safe vaccine to protect patients at risk from smallpox.

Jenner is now regarded as the “Father of Vaccination.” Later Louis Pasteur developed and tested clinically an attenuated form of rabies that was less virulent but cured the disease as opposed to only protecting against subsequent infection. In 1901 von Behring received the first Nobel Prize in Medicine for his discovery of what would come to be known as antibodies.

Although Vaccinia was eliminated from the international scene as recently as two decades ago, terrorism fears have generated renewed interest in the large-scale protection of an unprotected population against the disease, which has occasionally reappeared as a result of laboratory accidents and, in some cases, of deliberate dissemination of the virus. This is one example of the primary need for protection against the disease and for suitable vaccine delivery systems.

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