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Vaccination and Immunization. To what extent do vaccinations affect the human immune system?. Background. 1796 – Edward Jenner used pus from cowpox to inject into a boy The weak cowpox disease was similar to smallpox, so vaccination caused immunity towards smallpox
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Vaccination and Immunization To what extent do vaccinations affect the human immune system?
Background • 1796 – Edward Jenner used pus from cowpox to inject into a boy • The weak cowpox disease was similar to smallpox, so vaccination caused immunity towards smallpox • Louis Pasteur developed the idea into what we know as vaccinations today • From creation of vaccines, diseases that were once fatal were eradicated (smallpox) and decreased occurrence of other diseases dramatically • Today, vaccines for diseases like diphtheria, measles, rubella, polio and many more are available
How Vaccines Work • Vaccines prepare the body for a particular disease so that the immunity towards it increases • Two types: prophylactic (preventing disease) or therapeutic (fighting diseases) • Use weakened or dead viruses in vaccines to inject into bloodstream • For many viruses, multiple vaccinations are required to ensure full immunity
Antigens are generated and cultured either 3 different ways • in chicken eggs; • cell cultures or; • baculovirus(virus that only affect fall army worms) – still in development • All are mediums for antigens to grow in • Once generated, antigens are isolated from the cells, purified, and put into vaccines • Along with antigen, combination of chemical excipients (inactive substances used as carriers) and preservatives are added
Taken from: Bonnie Berkowitz, Brenna Maloney and Laura Stanton - The Washington Post http://www.washingtonpost.com/wp-dyn/content/graphic/2009/11/24/GR2009112401834.html?hpid=moreheadlines
Aluminum • Added as adjuvants to stimulate earlier, more potent and persistent antigen response • Antibiotics • Prevent growth of bacteria during production and storage • Formaldehyde • Inactivates bacterial products for toxoid vaccines • Kills unwanted viruses and bacteria that may contaminate vaccine • Monosodium glutamate (MSG) & 2-phenoxy-ethanol • Stabilizers to help vaccine remain unchanged when exposed to heat, light, humidity, or acidity • Thimerosal (mercury) • Preservative to prevent contamination and growth of bacteria
Two types of acquired immunity: active (response to exposure), and passive (immunity introduced by antibodies from outside source) • White blood cells (Lymphocytes) are in charge of immunity in body • Bone marrow creates B-cells • B-cells produce antibodies • Thymus makes variety of T-cells • Helper T-cells interact with B-cells to produce antibodies • Killer T-cells responsible for immunity • Suppressor T-cells suppress antibody production
Vaccines introduce weakened antigens (invading microorganisms) into bloodstream and B-cells recognize the foreign antigens and bind to it • B-cells then take in antigen by endocytosis and express it on plasma membrane in the MHC protein (Major Histocompatibility Complex), a unique marker protein • Macrophages (white blood cells) then engulf the antigens and express it on MHC • Helper T-cells with receptors for the specific antigen come into contact with macrophage and become activated B-cell budding virus (Analytical Imaging Facility at the Albert Einstein College of Medicine, 2005-2007). Taken from http://www.einstein.yu.edu/aif/gallery/sem/sem.htm
Activated helper T-cell binds to B-cell with the specific antigen and activates B-cell • Activated B-cell rapidly divides and forms clones of plasma cells that create antibodies to fight antigens (Pierce, 2002). Taken from Nature Reviews Immunology http://www.nature.com/nri/journal/v2/n2/fig_tab/nri726_F1.html
When antigens are killed, antibodies disappear from blood and few activated B-cells and helper T-cells remain as memory cells • Vaccination lets body undergo primary response against specific antigen (myDr, 2005). Taken from http://www.mydr.com.au/travel-health/vaccination-and-antibodies • When the stronger version of the virus is exposed to the body, the memory cells will recognize the protein coat and instantly clone plasma cells much more rapidly to fight the virus • This secondary response is much faster compared to the primary response
Polio • Causes acute paralysis, permanent physical disability, or death • With vaccination, more than 350 000 cases of polio from 1988 decreased to 2000 cases in 2006 • Meningitis • Causes bacteria in the blood, pneumonia, or inflammation of the epiglottis (potentially closing the windpipe) • Survivors are left with deafness, seizures, or mental retardation • With vaccination, incidence of Meningitis declined 98% from 1987 • Hepatitis B • Increases chance of chronic liver disease or cancer, and cirrhosis(loss of liver function) • With vaccination, declined from 450 000 in 1980s to 80 000 in 1999
Pertussis • Coughing spells lasting for extended periods of time, inducing vomiting • Can cause pneumonia, brain damage, seizures, and mental retardation • In countries with anti-vaccine movements on pertussis, incidence increased 10 to 100 times the rates in countries with vaccinations • Rubella • Causes heart defects, cataracts, mental retardation, and deafness
Diphtheria • Bacterium in body producing a toxin that affects the heart and nerves • In U.S. cases dropped from 206 000 in 1921 to 2 in 2001 • Tetanus • Tetanus-causing bacteria distributed in soil and street dust and resistant to heat and germ-killing cleaners • Larynx closes causing breathing difficulty, causes stiffness or spasms in muscles that can create fractures in spine and long bones; some go into a coma • Not contagious but widespread in environment
Safety • Since the creation and use of vaccines, there have been questions about morality, ethics, effectiveness and safety of them • Critics say the safety tests for vaccines are inadequate • Creates risk of fatal adverse effects including death or development of rare diseases • Some believe vaccines are related to autism although research disproves this • Some vaccines contain mercury, dangerous/ poisonous to the body • Mercury-containing vaccines are being replaced with new mercury-free vaccines
Moral and Ethical • Vaccination goes against some religious beliefs; many political groups against mandatory vaccinations due to this • Mandatory vaccinations are perceived to infringe on individual liberty • Those unvaccinated create threat to widespread population; herd immunity is decreased • Vaccines contain animal products, are cultured on animal mediums, and tested on animals
Economical • Pharmaceutical companies producing vaccines are financially motivated • Diseases with most needed vaccines like HIV, malaria and tuberculosis are expensive and needed in less developed countries • Companies do not produce many of these vaccines because of the minimal profit
Vaccinations prevent dangerous diseases effectively • Compared to the chance of receiving the actual disease, chance of adverse effects are minuscule • Helped eradicate smallpox, decreased cases of other diseases dramatically before vaccination, as well as creates herd immunity • Studies show that chances of receiving disease without vaccination is much higher than a vaccinated individual
Bibliography • Berkowitz, B., Maloney, B., & Stanton, L. (2009, November 24). Three ways to make a Vaccine. The Washington Post. Retrieved January 6, 2011, from http://www.washingtonpost.com/wp-dyn/content/graphic/2009/11/24/GR2009112401834.html?hpi • Damon, A. (2007). Biology: standard level : developed specifically for the IB diploma. Harlow, Essex: Pearson Education. • Pierce, S. (n.d.). Figure 1 : Lipid rafts and B-cell activation : Nature Reviews Immunology. Nature Publishing Group : science journals, jobs, and information. Retrieved January 6, 2011, from http://www.nature.com/nri/journal/v2/n2/fig_tab/nri726_F1.html • SEM (Scanning Electron Microscopy). (n.d.). Albert Einstein College of Medicine | Medical Education | Biomedical Research. Retrieved January 6, 2011, from http://www.einstein.yu.edu/aif/gallery/sem/sem.htm • Stern, A., & Markel, H. (2005, May). The History Of Vaccines And Immunization: Familiar Patterns, New Challenges . Health Affairs, 24, 611-621. Retrieved January 6, 2011, from http://content.healthaffairs.org/content/24/3/611.full • Vaccination and antibodies - myDr.com.au. (n.d.). myDr.com.au - Health and Medical Information for Australia from MIMS. Retrieved January 6, 2011, from http://www.mydr.com.au/travel-health/vaccination-and-antibodies • Vaccines: HOME page for Vaccines and Immunizations site. (n.d.). Centers for Disease Control and Prevention. Retrieved January 6, 2011, from http://www.cdc.gov/vaccines/ • Wolfe, R., & Sharp, L. (2002, August 24). Anti-vaccinationists past and present. National Center for Biotechnology Information. Retrieved January 6, 2011, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1123944/?tool=pmcentrez