1. Specific, non-specific defense and vaccines

2. The Immune System is the Third Line of Defense Against Infection11

3. Immunity Specific defenses Immunity Active immunity Passive immunity
Following clinical infection
natural
Transfer of maternal
Antibodies Through placenta
Following subclinical infection
Transfer of maternal
Antibodies Through milk
acquired
Following vaccination
Following administration of
Immunoglobulin or antiserum 10

4. Active immunity
Resistance developed in response to stimulus by an antigen. 9

5. Passive immunity
Immunity conferred by an antibody produced in another host. 8

6. The Immune Response
Immunity: Ability to recognize and defend against specific pathogens or antigens.
Immune Response: production of antibodies and specialized lymphocytes
Antigen: Molecules that provoke a specific immune response.
Pathogen – foreign organism 7

7. Innate or Genetic Immunity: Immunity an organism is born with.
Acquired Immunity: Immunity that an organism develops during lifetime. 6

8. Components of Human Immune System5

9. Types of Acquired Immunity
II. Artificially Acquired Immunity: by vaccine
1. Active
Antigens from vaccines (immunization).
Body makes immune response.
Immunity can be lifelong or temporary
2. Passive:
antibodies (antiserum) introduced by injection.
Snake antivenom injection from horses or rabbits.
Immunity is short (half life three weeks).
Host immune system does not respond to antigens. 4

10. Antibodies are Produced by B cells Lymphocytes3

11. Antibodies are Proteins that Recognize Specific Antigens2

12. Duality of Immune System
I. Humoral (Antibody-Mediated) Immunity
antibodies are made to fight antigens.
Antibodies are made by lymphocytes called B cells.
Stimulated B cells will secrete antibodies called plasma cells.
Antibodies are found in extracellular fluids (blood plasma, lymph, mucus, etc.) and the surface of B cells.
Defense against bacteria, bacterial toxins, and viruses that circulate freely in body fluids, before they enter cells.
Also cause certain reactions against transplanted tissue. 1

13. End day one notes

14. II. Cell Mediated Immunity
specialized lymphocytes called T cells
Helper T cells
Cytotoxic T cells
T cells regulate proliferation and activity cells in the immune system: B cells, macrophage, etc.
Defense against:
Bacteria and viruses that are inside host cells and are inaccessible to antibodies.
Fungi
Cancer cells
Transplanted tissue 14

15. Cell Mediated Immunity is Carried Out by T cells13

16. How Do B Cells Produce Antibodies?
B cells-- develop from stem cells
mature B cells migrate to lymphoid organs
Clonal Selection: B cell recognizes, stimulates and divides into plasma cells, secrete antibodies.
antibodies recognize only one antigen. 11

17. T Cells and Cell Mediated Immunity
Antigens that stimulate this response are mainly intracellular.
Requires constant presence of antigen to remain effective.
Unlike humoral immunity, cell mediated immunity is not transferred to the fetus. 10

18. T Cells and Cell Mediated Immunity
Cellular Components of Immunity:
T cells have an antigen receptor
recognizes and reacts to a specific antigens
major histocompatability (MHC) proteins on the surface of cells.
Clonal selection increases number of T cells. 9

19. T Cells Only Recognize Antigen Associated with MHC Molecules on Cell Surfaces8

20. T Cells and Cell Mediated Immunity Types of T cells
1. T Helper (TH) Cells: Central role in immune response.
Recognize antigen
Activate macrophages
Induce formation of cytotoxic T cells
Stimulate B cells to produce antibodies. 7

21. Central Role of Helper T Cells6

22. Types of T cells (Continued)
2. Cytotoxic T (Tc) Cells: Destroy target cells.
Recognize antigens on the surface of all cells:
Kill host cells that are infected with viruses or bacteria.
Recognize and kill cancer cells.
Recognize and destroy transplanted tissue. 5

23. Humoral Response to T Dependent Antigens4

24. Overview of the Immune Response3

25. Vaccination
Vaccination is a method of giving antigen to stimulate the immune response through active immunization.
A vaccine is an immuno-biological substance designed to produce specific protection against a given disease.
A vaccine is “antigenic” but not “pathogenic”. 2

26. Periods of maintained immunity due to vaccines
Short period (months): cholera vaccine
Two years: TAB vaccine
Three to five years: DPT vaccine
Five or more years: BCG vaccine
Ten years: yellow fever vaccine
Solid immunity: measles, mumps, and rubella vaccines. 1

27. Levels of effectiveness
Absolutely protective(100%): yellow fever vaccine
Almost absolutely protective (99%): Variola, measles, mumps, rubella vaccines, and diphtheria and tetanus toxoids.
Highly protective (80-95%): polio, BCG, Hepatitis B, and pertussis vaccines.
Moderately protective (40-60%) TB, cholera vaccine, and influenza killed vaccine.