1. Immune system dynamics

2. Figure 17.1

3. Antibody- antigen binding Figure 17.1 Antigens (Ag) Protein or polysaccharide Can be attached or free from cell Antibodies (Ab) Globulin proteins Specific for 1 (one) Ag Lymphocytes B and T cells B cells produce Ab

4. Figure 17.1 How do we acquire immunity? 1. Humoral immune response 2. Cell-mediated immune response

5. Humoral Immunity- fighting antigens in the blood The players involved: - An antigen - B cell with specific Ab - Helper T cells The product: - Antibodies - Clone army of B cells and T cells specific for the antigen

6. Figure 17.5 - Overview How is a clone army made?

7. Primary vs. secondary exposure

8. The players involved: - Infected host cells - Cytotoxic T cells - Helper T cell The product: - Target and kill infected host cells Cell-Mediated Immunity: the fight against antigens inside our own cells

10. What cell type is necessary for both processes?

11. Helper T cells

12. Human Immunodeficiency Virus (HIV) infects Helper T cells

13. What happens when HIV infects helper T cells?

15. How could we prevent HIV infection from progressing to disease?

16. Vaccination!

17. What is a vaccine? Attenuated whole-agent vaccines- weakened microbes (measles, mumps, rubella, chickenpox…) Inactivated (killed) whole-agent vaccines- killed microbes (polio, rabies, pertussis) Toxoids- inactivated toxins (tetanus, diptheria, pertussis) Subunit vaccines- partial antigenic fragments of microbes (hepatitis B) Conjugated vaccines- polysaccharides combined with proteins (H. influenza b)

18. Current vaccination schedule

19. Why not vaccinate? -Complacency about disease -Benefits of vaccination not immediately evident (adverse reactions are immediate) -Media’s role -Need to link tragic events (eg. autism) with cause -Philosophical beliefs based on above -Vaccines don’t work. -Why vaccinate when the disease is so rare? -Vaccines cause secondary disease.

20. Vaccine success story- smallpox -Caused by variola virus (major and minor) -First disease for which immunity was artificially induced -Last case in 1977 Source: Centers for Disease Control and Prevention

21. -Measles caused by Rubeola virus -Symptoms: fever, rash, conjunctivitis, pneumonia, encephalitis (permanent damage), death -Pre-vaccine: 3-4 million cases annually, 450 deaths, 28,000 hospitalizations, 1,000 children with chronic disabilities (US ONLY) -Highly contagious: requires > 90% vaccination coverage in population -Currently leading cause of death from a vaccine-preventable disease (In 2010, there were 139,300 measles deaths globally – nearly 380 deaths every day or 15 deaths every hour) http://www.who.int/mediacentre/factsheets/fs286/en/ Refusing vaccines- who suffers?

22. Vaccines… the bottom line -Vaccines work! A total 98.8% reduction in vaccine preventable diseases in the US since vaccination schedule was implemented. -Exemptors of vaccines break down herd immunity and increase risk of disease on a population level -Vaccines will never be 100% effective or 100% safe -It is a personal choice, but be aware that one’s choice affects the rest of the community SO GO GET YOUR FLU SHOT! AND BE SAFE AND HAVE A VERY HAPPY HOLIDAY SEASON!