Every now and then you may here about vaccines when it comes to curing a disease. Many people make different assumptions about it but don’t know the real concept lying behind vaccination. In many countries many people still think that getting a vaccine may make your health condition even worse. Do you want to know how this technique came into existence and helped to treat many diseases? In this report, we are going to understand briefly about the story of discovery and how vaccine is made.
What is a vaccine and how it is made?
Most of us have heard people saying that diseases like chicken pox occurs only once in a lifetime or you may say it that the next time you get infected by certain microbes the health condition doesn’t get effected like the first time. So the mechanism lying behind it is nothing but the involvement of immune system. The first time our body interact with any microbe it lead to activation of our immune system and as a result antibodies are produced against the microbe. Our immune system memorize the microbe and later on when our body is infected with the same microbe the activation of immune system take less time and also the antibodies produced in the first infection helps to kill the microbe in future infections.
This natural phenomenon is used in the production of vaccine. So the vaccine is made by biological preparation of an attenuated microbe which will help to attain acquired immunity against that particular microbe.
Story of vaccine discovery
In ancient ages people used to think that any disease caused to humans was due to some supernatural event that involved devils. This thought brought a fear of destruction and so became an effective tool for rulers and politicians to instil terror, which made it useful in controlling human behaviour.
Edward Jenner observed a phenomenon in the ancient Chinese practice of preventing diseases that were similar to her observation in milkmaids. The milkmaids who were infected with the cowpox virus was protected against small poxvirus. Lay people, such as farmers practiced it by themselves by inoculating their family with the cowpox pus to prevent smallpox, well before the time of Jenner without knowing the reason behind it. Edward Jenner with such background knowledge conducted the first investigations of smallpox prevention by human experimentation in 1796. These clinical studies proved that the pre inoculation of the cowpox virus did prevent smallpox virus. This led to the beginning of the sciences of both vaccinology and immunology.
The use of cowpox vaccination became famous in Europe and North America without knowing how the vaccine is made but after that there was no new vaccine discovery for more than a century and a half as at that time people didn’t know the relation between disease and microbe. They believed in the theory of spontaneous generation i.e production of living organisms from non-living matter.
It is very interesting that the greatest discoveries of science mostly comes from small observation and sudden accidents. The practical use of how the vaccine is made belongs to one of those small observations. The French chemist, Louis Pasteur was conducting an experiment by growing the bacterium in the laboratory that was thought to cause fowl cholera. He cultured the bacteria and then injected it in chickens to show that chickens injected with the cultured bacterium developed cholera. After culturing the bacteria, he went for a summer vacation and after he returned and injected some chickens with an old culture. He observed that though the chickens became ill, but he was surprised to see that they recovered very fast.
It made him very curious and so Pasteur reconducted the experiment and grew a fresh culture of the bacterium an inject them in fresh chickens. But destiny wanted something different and so there was a shortage of chickens and therefore he used the previously infected chickens. He was surprised and shocked to see the result that, the chickens were completely protected from the disease.
Pasteur started to think about the observation and soon came to a conclusion that old culture aging had weakened the microbe and proved later on that such an attenuated strain might be administered to protect against the disease. Soon he named this attenuated strain a vaccine which means cow in latin. It was named in the honor of Jenner’s work with cowpox inoculation.
In 1885, Pasteur administered his first vaccine to a human, thus the first vaccine against rabies was produced. The fourth quarter of the nineteenth century was a period of the great awakening in which the meaningful science of vaccinology was born. After that there was no turning back and many vaccines are made against many diseases, produced by different researchers and thus saved many people’s lives.
If you like this blog stay tuned to know more about vaccines in the series of vaccines and also have a look at our previous blogs.
Hilleman, M.R., 2000. Vaccines in historic evolution and perspective: a narrative of vaccine discoveries. Vaccine, 18(15), pp.1436-1447.