Benefits of Vaccination - Research Paper Example

?Childhood Vaccination: Advantages and Disadvantages Introduction Vaccination, also called as immunization, is a method in which specific protection is provided against common and dangerous pathogenic organisms by stimulating the immune system to produce antibodies or T cells against the pathogenic organisms or the toxins of the organism, so that infection due to the organism does not manifest as a disease (Ghaffar and Haqqi, Microbiology and Immunology On-line). Vaccination was first developed by Edward Jenner, the first vaccine being against the deadly small pox, in the year 1796 (Ghaffar and Haqqi, Microbiology and Immunology On-line). It was he who coined the term 'vaccination'. The next vaccine was developed by Louis Pasteur against rabies in 1885, almost a century later. From then on, several vaccines have been developed which have helped in the control of several infectious diseases. During vaccination, an antigenic material is introduced into the body that evokes immune response to the host similar to the one that occurs when the infectious agent enters the body. Thus, when the individual is presented with the concerned pathogen, the already present immune response prevents the pathogen from either entering the body or evoking a disease process of both (Shah, Nitin and Kukrej, 2007). The antigens introduced for vaccination purpose either resemble the pathogen against which the immune response is expected, or are non-viable or attenuated forms of the pathogen. Since the time of introduction of vaccines, several diseases have been able to be controlled. Small pox could be eradicated mainly because of vaccination. However, vaccination is still a debated topic in several corners, eliciting medical, religious, political and ethical implications. Vaccination is associated with several disadvantages too because of which, many researchers often wonder if vaccination is necessary for mankind. In this essay, the advantages and disadvantages of vaccination will be discussed through review of suitable literature. Benefits of vaccination Vaccines mainly act by eliciting immunity against a particular disease. There are basically 2 types of immunity and they are innate and acquired. While the former develops after actual exposure to the disease, acquired develops following exposure to vaccination and this may be passive or active. Passive immunity occurs when the antibodies against a particular organism are directly injected into the body. Active immunity develops when antibodies are produced by the individual itself after providing an antigenic stimulus. While passive immunity offers short-term protection, active immunity renders long term protection. Examples of passive immunity are administration of anti-rabies serum following exposure to rabies. The vaccinations given in the immunisation schedules are examples of active immunity. Depending on the which type of T-lymphocyte series which are stimulated, the immune response can be humoral, cell mediated or both. Each vaccine is given at a distinct time, dose and schedule. The timing of any vaccine is based on susceptibility to the disease, presence of maternal antibodies and reactogenecity. Thus oral polio vaccine, hepatitis B and BCG vaccines are given at birth, because of lack of maternal immunity to diseases protected by the vaccines, tuberculosis, Hepatitis B infection and Polio. Diphtheria, pertussis and tetanus are given in early childhood in order to provide maximum reactogenecity and effective protection against these diseases (Shah, p.14). The advantages of childhood vaccinations are innumerous and it is because of these advantages that most countries in the world have adopted vaccination as a main strategy to prevent childhood diseases in their public health policies. There is no doubt that vaccination is the best strategy to prevent certain types of infectious diseases in newborns, infants, children and even adults who are vulnerable to some diseases. In some cases, despite vaccination, disease due to the pathogen may manifest. In these cases, the duration and severity of the disease is much lower, thus proving vaccination to be beneficial even in cases which have failed to complete immune response against the pathogen. prevented by vaccination. Disease Total cases Year Cases in 1994 % Change Diphtheria 206,939 1921 2 -99.9% Measles 894,134 1941 963 -99.9% Mumps 152,209 1968 1537 -99.9% Pertussis 265,269 1934 4617 -99.9% Poliomyelitis* 21,269 1952 0 -100% Rubella 57,686 1969 227 -99.9% Tetanus 1,560 1923 51 -99.9% Table-1. Effect of vaccination on the occurrence of diseases (users.rcn.com) Live vaccines, which are attenuated forms of the pathogens trigger all phases of the immune system,thus conferring more stable immunity. It is for this reason that most live attenuated vaccines need no boosters. These vaccines are not only cheap but also easy to transport. Sabin oral polio vaccine of this genre can be given orally (Shah, p.19). Vaccine against tuberculosis, the Bacillus Calmette Guerin vaccine or BCG is the only vaccine against the disease. The vaccine elicits cell-mediated immunity in the host. Actually, the protective effect following administration of this vaccine is not very good. The protective effect against development of pulmonary tuberculosis is less than 50 percent. However, for whatever benefits it provides, this vaccine is recommended in countries with high prevalence and incidence of the disease like India. Another advantage of this vaccine is that it decreases the risk of developing more dangerous forms of tuberculosis, the miliary tuberculosis and disseminated tuberculosis (National Tuberculosis Advisory Committee). Thus vaccination is associated with several advantages. Disadvantages Despite the proven advantages of vaccination, there are several disadvantages too which are a source of concern to most health experts and parents of children. Critics have always disputed the safety of vaccination. Vaccines are mainly selected based on the necessity, safety and efficacy and they obtain license for human use only after undergoing 3 phases of trials. During the first phase, the trials are done on human volunteers for evaluation of various tolerance and safety aspects. During the second trial, safety and immune response is checked in human volunteers and in the third trial, field efficacy and safety is again checked. Following these 3 rail phases, both the manufacturer of the vaccine and the Drug controller of the country test the purity, potency and sterility of the vaccines. Vaccines are released into the market only after they have passes successfully in all these tests. However, despite all these efforts to keep human safety intact, some adverse events after vaccination have been reported. These events can be mild or severe. The most common adverse effect to any vaccination is redness and soreness at the site of injection. Other side effects include malaise, discomfort and fever. The type of side effect depends on the vaccine. For example, BCG vaccine causes formation of papule, ulcer and scarring at the site of injection. Actually, development of these features is considered as an indication of successful vaccination. However, BCG vaccine can illicit even worse reactions like lymphangitis, delayed healing of ulcer, abscess formation, enlargement of ipsilateral cervical and axillary lymph nodes, osteomyelitis and disseminated BCG vaccination. Another vaccine associated with notorius side effects is DPT vaccination. , more than 40 percent of individuals develop some adverse reaction or the other following DPT vaccination. The most common side effect is soreness and pain at the site of administration of the vaccine. The pain can be so severe that it can cause excessive crying and inability to move the limb. Induration, fever and swelling can also develop and fever can last 24- 72 hours after vaccination (Shah, p.12). Rarely, in some individuals, vaccination can also cause an anaphylactic reaction and evoke a neurological response like seizures. DPT can also lead to systemic side effects like irritability, anorexia, vomiting, excessive crying and lassitude. these side effects are mainly due to pertussis vaccine. In rare cases, even seizures can occur. Measles and varicella vaccines can lead to rash and fever (Shah, p.18). While these adverse effects can be tolerated, some reactions can be nasty. For example, a particular type of vaccine against swine flu is associated with reactions like anaphylactic shock, Gullain Barre syndrome, vasculitis, Shock, paralysis and even death (Menzies et al, p.365). Vaccine against pneumococcus, the polysaccharide pneumococcal vaccine can lead to convulsions and even anaphylactic shock (Haber et al, p.309). Another vaccine worth mentioning at this juncture is the vaccine against Japanese encephalitis. The disease is a zoonotic viral disease rampant in Asia. The vaccine against this disease is an inactivated vaccine developed from the infected brain tissue of mouse. The vaccine is not only expensive but needs to be given in multiple doses. This vaccine is notorious for significant and dangerous adverse reactions. To combat the cost and adverse reactions of this vaccine, a cheaper form of vaccine, with strain SA 14- 14- 2 has been developed in China and Korea. But there are not many trials to ascertain the benefits and safety of this vaccine (Plesner, p.669). Other than safety aspects, not all vaccines are efficacious and BCG is a classical example in this regard. hence this vaccine is not recommended in the United States (CDC, 2009). In case of varicella vaccination, experts are of the opinion that natural infection with varicella offers lifelong protection against chicken pox and administrtion of vaccine for this purpose, defeats the purpose. , there is some evidence based on studies that universal infant vaccination with varicella vaccine can cause a surge in chicken pox in adulthood and pregnancy. Based on these studies, experts are of the opinion that though chicken pox vaccination prevents economic loss due to loss of work time, health care costs may arise (Ferson, p.3). However, some experts argue that the surge can be minimised by using multiple doses (Senterre, p.A223). Varicella has been used as a combination with other vaccines, measles, mumps, and rubella, but this combination vaccine has merited several critical points because of increased risk of febrile seizures. Another major disadvantage of vaccination is the cost which many experts argue that they the vaccination may not be that beneficial viewing the cost-benefit analysis. A good example for this is the cervical cancer vaccine, which is the vaccine against human papilloma virus or HPV virus. The cost of vaccination is about 100 dollars and the efficacy is only 70 percent. Girls less than 12 years of age are encouraged to take the vaccine while the risk of cancer occurs much later in life and is dependent on several factos including promiscuity. Also, in view of not-so-high efficacy of the vaccine, screening for cervical cancer is mandatory despite vaccination. The vaccine has to be given in 3 doses and many people cannot afford the price (Madrid-Madrina, p.471). Some vaccines, especially the live attenuated vaccines are difficult to be transported and these are at increased risk of secondary mutation which can be highly virulent. Live vaccines can actually cause disease in immunosppressed individuals and during routine vaccination in childhood, the physician is yet unaware of the immune status of the young infant. It is for these reasons that live oral polio virus vaccine is being gradually replaced by inactivated polio vaccine (Ghaffar and Haqqi, Microbiology and Immunology On-line). One vaccine which has gained lot of criticism and evaluation from all corners is the MMR vaccine. This vaccine is a combined vaccine that offers protection against the viral exanthematous illnesses, measles, mumps and rubella. After its introduction in 1988, it has caused dramatic reduction in the incidence and mortality related to these diseases (NHS, 2009) , prior to introduction of this vaccine, the most common cause of viral memningitis was mumps. The vaccines have also decreased the incidence of congenital diseases related to these viruses. Thus, it can be said that MMR is an effective vaccine. The antigens in this vaccine are inactivated live viruses of the respective diseases. Several concerns have been raised by critics and medical experts about the actual benefits of this vaccine to humankind. This is because; the vaccine is associated with several complications like Gullai- Barre syndrome, autism, Crohn's disease and subacute sclerosing panencephalitis (Mediinfo, 2004). A major study by Wakefiled et al was published in Lancet which proved an association between autism and MMR vaccine. This study reported that MMR vaccine was associated with risk of development of enterocolitis and autism-spectrum diseases. Following this study, the UK government discontinued the use of MMR vaccine until further research. This led to rise in the infectious diseases and associated morbidity and mortality (NHS, 2004). Several studies and research followed this study which led to interesting developments. One was that the original report was based on conflicts of interest that were undeclared and hence the report was invaluable. The department of health of UK opined that no association between autism and MMR vaccine can be made. Also, since there is no sudden surge of autism after introduction of the vaccine, autism cannot be related to the vaccine. Extensive studies which involved many children, carried out in various parts of the world including the UK and the US have not been able to prove any association between the vaccine and autism (NHS, 2004). CDC (2007) opined that the most common cause of autism is genetic predisposition and that the chances of a child who received MMR is at a similar risk as that who has not taken the vaccine. CDC (2007) recommends combined vaccine against MMR because "in the time gaps between the three vaccines, children would not be protected against the diseases they had not yet been immunized against. So there would be an increase in measles, mumps and rubella leading to illness and possible death. Also, unprotected children can pass on these diseases to other at risk children and pregnant women." Conclusion Thus vaccination is associated with several advantages and disadvantages. However, it is an undoubted fact that vaccination has caused a drastic reduction of infectious diseases in children and related morbidity and mortality. This is a vaccination era and control of development and spread of deadly infectious diseases in infants, children, adolescents, adults and elderly has been possible only though universal acceptance and approach of vaccination. However, vaccination is associated with several individuals disadvantages like discomfort, cost, pain and tenderness at the site, rah, fever and even worse side effects like seizures and death. For the community, vaccination can cause shift of development of the diseases to adulthood, emergence of mutant pathogens and emergence of newer problems like vaccine derived paralytic polio. Works Cited Page CDC. “Measles, Mumps, and Rubella (MMR) Vaccine and Autism Fact Sheet.” Department of health and Human Services, 2007. Web. 7 April 2011. http://web.archive.org/web/20080407015528/http://www.cdc.gov/vaccinesafety/concerns/mmr_autism_factsheet.htm CDC. “Fact Sheets: BCG Vaccine.” 2009. Web. 7 April 2011. http://www.cdc.gov/tb/publications/factsheets/prevention/bcg.htm. Ferson, MJ. “Another vaccine, another treadmill?” J Paediatr Child Health, 2009. 31(1), 3-5. Ghaffar, A, Haqqi, T. “Immunization. Microbiology and Immunology On-line.” University of South Carolina School of Medicine, 2010. Web. 7 April 2011 http://pathmicro.med.sc.edu/ghaffar/immunization-ver2.htm. Haber, P, Sejvar, J, Mikaeloffm Y, DeStefano, F. “Vaccines and Guillain-Barre syndrome.” Drug Saf., 2009. 32(4), 309-23. Menzies, R, Mahajan, D, Gold, MS., Roomiani, I, McIntyre, P, Lawrence, G. “Annual report: surveillance of adverse events following immunisation in Australia, 2008.” Commun Dis Intell., 2008. 33(4), 365-81. Madrid-Madrina, V, Torres-Poveda, K, Lopez-Toledo, G, Garcia-Carranca, A. “Advantages and Disadvantages of Current Prophylactic Vaccines Against HPV.” Archives of Medical Research, 2009. 40(6), 471- 477. Mediinfo. (2004). MMR vaccination. Retrieved on 20th November, 2010 from http://www.medinfo.co.uk/immunisations/mmr.html NHS. “MMR: the facts.” 2004. Web. 7 April 2011. http://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/documents/digitalasset/dh_105189.pdf Plesner, AM. “Allergic reactions to Japanese encephalitis vaccine.” Immunol Allergy Clin North Am., 2003. 23(4), 665-97. Institute of Medicine (US) Immunization Safety Review Committee. “Immunization Safety Review: Vaccines and Autism.” Washington (DC): National Academies Press (US); 2004. Senterre, J. “Varicella vaccination.” Rev Med Brux.,2004. 25(4), A223-6. Shah, RC, Nitin, KS, and Kukreja, S. “IAP Guidebook on Immunisation.” 2007. Web. 7 April 2011. http://docs.google.com/viewer?a=v&q=cache:cI2JJxqqzagJ:www.iapindia.org/iapfiles/guidebook2007.pdf+IAP+guide+book+of+immunisation&hl=en&gl=in&pid=bl&srcid=ADGEESgHz5r8vkmjjK3EAIUMRz1sgarxFizRbJrRMtSygo5z4oPAf6HUHOu6c5DkiKD0HQiKqAQGs6YzzewvPfgNL-NAd9udMstuqVbnel5NG8hXwj3ORYRS7qg9BEzAtwAJ57lk_GU9&sig=AHIEtbR0fLccjlKMHI5j5ZuiL9A5ob-xIg. Wake, AJ, Murch, SH., Anthony, A, et al. “Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.” Lancet, 1998. 351, 637- 641. Read More