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Vaccines (The history of vaccines (An early form of vaccination,…
Vaccines
The history of vaccines
An early form of vaccination, variolation, was first documented in China in the 16th century. The technique consists of blowing powdered smallpox scabs into the noses of the healthy, which causes a mild case of smallpox, after which the person is immune to smallpox.
The method spread to Europe via the Ottomans, and, in 1796, Edward Jenner noticed that cowpox infections grants immunity to smallpox (hence the famed beauty of milkmaids). He was quick to make this practice widespread.
in 1885, Louis Pasteur developed the rabies vaccine. Rabies thus became the second disease for which a vaccine is available.
Throughout the 20th century, vaccines against many other diseases are invented, both serious afflictions like plague and TB, and childhood diseases like measles and mumps.
In modern day, technologies such as DNA recombination and novel delivery techniques makes vaccine inventions increasingly easy.
Vaccination is defined as the deliberate administration of harmless antigens of the pathogen in order to confer future immunity. The procedure works as follows:
- Toxoids, recombinant DNA, purified cell wall saccharides are harvested from the disease-causing organisms (in other cases, dead/attenuated bacteria and inactivated viruses are also used directly)
- The substance is then administered via injection, nasal spray, or by mouth.
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The body's immune system makes antibodies against the disease of the vaccine in an primary immune response, memory cells are obtained.
If the actual pathogen enters the body, the secondary immune response will destroy it rapidly.
Though numerous, notable diseases for which vaccines are available include:
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Edward Jenner tested hypothesis by deliberately infecting an 8-years old boy with cowpox using pus from an infected milkmaid, the boy then became immune to smallpox. He then tested this on 23 other people, including himself. His experimental procedures will not have been ethical by today's standards, for several reasons:
- He exposes an eight-year old boy, as well has his 11-month old son, to a known deadly disease. The boy is below the age of consent.
- He had not done any research or animal trials, and directly moved to testing his procedures on humans.
- The hypothesis is a controversial one, especially back then when bacteriology and microbiology is not widespread.
There are many benefits and drawbacks of vaccines, these include:
Drawbacks
- Mild side effects such as light fever and sore arm for 2 or 3 days in children.
- Possible allergic reactions to ingredients in vaccines.
- Vaccines are not guaranteed to provide 100% protection.
Benefits
- Eradication of many life threatening diseases such as smallpox and diphtheria.
- Active prevention of diseases, acquisition of active immunity.
- Vaccines are safely tested before they are introduced to the market, being monitored for every side effects.