Vaccination and Immunization

To what extent do vaccinations affect the human immune system?

By: Team 21

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 are made

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

• Stimulates the immune system to make antibodies and lymphocytes

• 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 Posthttp://www.washingtonpost.com/wp-dyn/content/graphic/2009/11/24/GR2009112401834.html?hpid=moreheadlines

What goes into a Vaccine?

• 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

What goes on in the Body?

• 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 fromhttp://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

• 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

(myDr, 2005). Taken from http://www.mydr.com.au/travel-health/vaccination-and-antibodies

Example Diseases

• 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 Primarily affects the skin and lymph nodes Causes heart defects, cataracts, mental

retardation, and deafness

• Diphtheria Bacterium in body producing a toxin that affects the

heart and nerves Contagious disease spread by direct physical contact or

breathing 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

Controversies

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

Importance of Vaccinations

• 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