Immunization was first introduced in 1796 by Edward Jenner and since then various diseases have had their vaccines licensed. This has seen a reduction in illnesses and death that often resulted from infection with these diseases. Various vaccines have received negative reception due to the severe side effects they elicit. However this has led to the development of better vaccines for example the pertussis and rota virus vaccines. Though almost all vaccines have side effects their benefits greatly outweigh their side effects.
Immunization is the method of stimulating a resistance response in a human or animal body to specific diseases that have been killed or have been attenuated. These microorganisms do not cause disease but rather boos the body’s immune system to fight the microorganism should it encounter it in future.
In order to better understand immunization we need to understand how immunization came about by studying its history. A major breakthrough in immunization occurred in 1796 when Edward Jenner a British physician realized that people who had suffered from cowpox did not get small pox a severe disease as compared to cowpox and which causes disfigurement and death. He did his research on an eight year old boy whom he inoculated with material obtained from the sores of a person with cowpox.
The boy did catch cowpox however on exposure to the small pox virus, he remained immune and did not catch the disease. This phenomenon has been explained that the cowpox antigen is so similar to the small pox antigen hence they make the body produce the same antibodies to both diseases hence the protection obtained from exposure to small pox after immunization with small pox.
This breakthrough was followed by that of Levis Pasteur in 1885 who discovered a vaccine for rabies. He made this realization on a boy who had obtained fourteen bites from a rabid dog. He injected the boy with more virulent rabies viruses into the boy giving him immunity to the virus (Clamer , C. H.;Shieck, V. 2008).
In mid 1900s Jonus Salk and Albert Sabin made great strides in developing a successful vaccine for the poliomyelitis various that was epidemic in some parts of the world for example Africa. Salk developed an injectable vaccine that contained the inactivated virus and Sabin developed the oral vaccine that contained attenuated that is live weakened virus. This development has led to the elimination of the polio virus in many parts of the world.
These breakthroughs have led to further development of immunization and immunization techniques with more and more viruses getting a vaccine. Immunization has led to a decreased in illnesses such as measles, mumps and tetanus and diphtheria.
Tetanus cases have also reduced tremendously. In the mid 1800s the US military personnel reported 20s tetanus cases per 100,000 wounds. Between 1922-1926 approximately 1,315 tetanus cases were reported annually. After the introduction of the vaccines public health officials tracked the number of tetanus cases and by 2000 only 41 tetanus cases were reported in the U.S
The introduction of a combined vaccine for the measles, mumps and rubella virus has seen a decrease in the spread of each of the mentioned diseases. Before the availability of a measles vaccine, an average of 450 measles – associated deaths were reported between 1953 and 1963. These deaths were as a result of complications arising from measles such as pneumonia and encephalitis s (Van Der Wouden, Bernsen ).
Cases of mumps which is characterized by a swelling of the parotid gland were on the rise before the mumps vaccine was reported. This resulted in deafness in children. Around 212,000 cases were reported in the US in 1964. The cases reduced rapidly after the vaccine was licensed in 1967. in 2001 only 266 cases of mumps were reported.
Between 1964-1965 there was an epidemic of rubella that saw about 20,000 newborns being born with the congenital rubella syndrome and other pregnancies resulting in neonatal deaths and miscarriages. Only forty cases of rubella in pregnant women have been reported since 1999.
Cases of diphtheria have also reduced significantly since the licensure of the Dtap vaccine. 206,000 cases and 15,520 deaths were reported in 1921. These figures fell significantly in 1923 after the introduction of this vaccine. Only two cases of diphtheria were reported in 2001.
Immunization has led to considerable benefits. One of the benefits is decreased mortality. Vaccines developed have seen a considerable decrease in the number of deaths resulting from the disease. In all those diseases that have vaccines all of them have reported a smaller figure of deaths as compared with the enormous figures that were reported before their introduction. A good example is the diseases discussed above, another example is the 9,000 pertussis –related deaths in US that were reported prior to the introduction of a pertussis vaccine. Since the introduction of the DTaP vaccine, fewer cases have been reported.
The other benefit is that there are fewer cases of disabilities as a result of immunizable illnesses. A good example is the reduction in disability cases arising from poliomyelitis. Before the vaccine was available 13,000-20,000 cases of paralytic polio were reported annually. The vaccine and an unanimous decision by the world Health Assembly to totally eradicate the virus worldwide led eradication of this virus in all countries except four that is Afghanistan, India, Nigeria and Pakistan. Mental disability as a result of brain damage by the measles and rubella virus have also reduced.
Immunization has also eased the financial strain experienced during illnesses. This is because with prevention less money is spent on hospitalization and drugs. The cost of a vaccine shot is definitely cheaper as compared to the expenses incurred in treatment and management of a disease (William, PD, Day T, 2008).
However immunization does have its risks. These risks can be minor for example a mild fever or soreness at the site of injection or they can be major. One out of every 600,000 cases of hepatitis B vaccine shot administered leads to severe allergic reaction ( anaphylaxis) it is characterized by hives, labored breathing and a fall in the blood pressure. The old whole cells pertussis vaccine has more risks than the hepatitis B vaccine. One out of 100 children who received this vaccine cried persistently and a fever greater than 1050 was reported in one out of every 330 doses. Seizures accompanied by fever occurred in one out of every 1,750 doses administered. This side effect necessitated the introduction of the new ‘acellular’ vaccine PTaP which has fewer side effects(Gangarosa EJ, 1998),(Hirtz D.G, Nelson Kb, Ellenberg JH, 1983).
The first rota virus vaccine had to be withdrawn because it caused a medical condition called intussusceptions is characterized by blockage of the intestines due to its folding into another section of the intestine. Out of the one million children who received this vaccine in the United States one in every 10,000 that is a total of 100 children got intussusceptions.
Various programs have been set up around the world to provide immunization. One of these programs is the world Health Organization. To be able to deal with challenges posed in global immunization, the WHO and UNICEF developed the global immunization strategy which targets to immunize more people. Its main goal is to reduce illness and death due to disease that can be prevented through immunization by 2015. it also aims to introduce new vaccines and technologies in immunization, to give critical health interventions and surveillance and to efficiently manage vaccination programs and activities globally.
The organization has set the goals it aims to achieve by 2015 or earlier. Among these goals is to sustain coverage reduce morbidity and mortality significance introduce new vaccines and ensure availability of vaccines of assured quality.
The centers for Disease control and Prevention (CDC) has also set up a National Immunization Program (NIP) which is focused on national and global efforts in the prevention of disease by providing public health leadership on vaccination issues.
The CDC also publishes the adult immunization schedule which helps to guide the adults through communication. This teaches adults abort the importance of immunization beyond childhood.
Conclusion
Immunization has been highly beneficial as it has reduced the high mortality and morbidity rates that were associated with the pre-immunization era. It has played a great role in worldwide development by ensuring that the population is healthy and also by reducing the financial strain that is usually experienced in the event of illness. Global programs such as UNICEF, WHO and the CDC have also played an important role in ensuring the worldwide immunization which leads to worldwide eradication of diseases(Neil Miller, 2008).
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