Lecture 11: Practical applications of immunology ; vaccinations Edith Porter, M.D. 1

 Major applications of immunology ▪ Vaccines ▪ Immunological memory ▪ Types of adaptive immunity ▪ Types of vaccines ▪ Development of new vaccines ▪ Safety of vaccines ▪ Generation of antibodies for research and diagnostic ▪ Anti-sera ▪ Monoclonal antibodies ▪ Diagnostic immunology ▪ Precipitation and agglutination reactions ▪ Complement fixation ▪ ELISA, western blot, immunofluorescence 2

 Once lymphocytes have encountered their specific antigen they undergo clonal expansion  Some of these cells develop further into memory cells  Can circulate for many years  Upon re-contact with the same antigen they quickly proliferate and resume effector function  B cells: antibody production  T cells: cytokine production (TH, Treg) and cytotoxicity (CTL)  Instead of requiring 10 – 14 days for a full response measurable effects appear within 2 days 3

4  IgM is always the first antibody  IgG follows IgM  IgG level does not go back to baseline  Re-exposure to the same antigen will lead to an augmented and accelerated immune response, increased IgG response and with higher residual antibody levels  Presence of antibodies is not equivalent to sickness Primary Response Secondary Response

5 Vaccines do not always target B cells and antibodies but some target T cells.

Naturally acquired  Active immunity  Resulting from infection  Passive immunity  Transplacental  Colostrum Artificially acquired  Active immunity  Injection of Ag (vaccination)  Passive immunity  Injection of Ab Vaccines: toxoid, killed microorganisms, live attenuated microorganisms Long Lasting Short Lasting 6

 1) What type of immunity results from vaccination?  A) Innate immunity  B) Naturally acquired active immunity  C) Naturally acquired passive immunity  D) Artificially acquired active immunity  E) Artificially acquired passive immunity  3) What type of immunity results from recovery from mumps?  A) Innate immunity  B) Naturally acquired active immunity  C) Naturally acquired passive immunity  D) Artificially acquired active immunity  E) Artificially acquired passive immunity  15) The antibodies found in mucus, saliva, and tears are  A) IgG.  B) IgM.  C) IgA.  D) IgD.  E) IgE.  26) The best definition antibody is  A) A serum protein.  B) A protein that inactivates or kills an antigen.  C) A protein made in response to an antigen that can combine with that antigen.  D) An immunoglobulin.  E) A protein that combines with a protein or carbohydrate. 7

 Induce active immune response with a related or inactivated agent that does not cause major disease  Induce cross-reactive antibodies or T cells  Herd immunity is sufficient to prevent epidemic diseases  Must weigh the benefit of protection versus the danger of vaccine associated disease 8

 Attenuated whole agent vaccines  Live, weakened microbes  Generated through long term culture  Mimic most closely actual infection  Caution: danger of backmutation to a virulent form  Dangerous for immunocompromised patients!  Inactivated whole agent vaccines  Toxoid 9

 Subunit or acellular vaccines  Use of antigenic subunit that triggers an immune response.  Inherent safer as it cannot reproduce in the host  Conjugated vaccine  Combine as antigen poorly immunogenic material (e.g. capsules) with an immunogenic protein  Nucleic acid vaccines (DNA vaccines)  Introduce genes for protein targets into the host  Host will express the protein and mount an immune response to this foreign protein 10

 Classical  Bacterial culture  (Animal extract)  Cell culture  Embryonated eggs  New Developments  Recombinant vaccines  Plants Influenza virus grown in embryonated eggs 11

 Improve effectiveness of vaccines/immunizations by providing co- stimulatory signals for T and B cells  In humans ▪ Alum ▪ Oil based substance MF59 and virosomes  In animals ▪ Freund’s complete adjuvants ▪ Mycobacterium extract 12

 Diphtheria: Purified diphtheria toxoid  Pertussis: Acellular fragments of B. pertussis or antigenic acellular fragments  Tetanus: Purified tetanus toxoid  Meningococcal meningitis: Purified polysaccharide from N. meningitidis  Haemophilus influenzae type b meningitis: Polysaccharides conjugated with protein  Pneumococcal conjugate vaccine: S. pneumoniae antigens conjugated with protein 13

 Influenza: Inactivated or attenuated virus  Measles: Attenuated virus  Mumps: Attenuated virus  Rubella: Attenuated virus  Chickenpox: Attenuated virus  Poliomyelitis: Inactivated virus  Hepatitis B: Antigenic fragments (recombinant)  Smallpox: Live vaccinia virus  Rabies: Inactivated virus  Hepatitis A: Inactivated virus  Human papilloma virus: Antigenic fragments Selected patients 14

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 Re-administration of vaccine to boost immune defense ( )  Increased antibody production  Increased memory cell development Time Ab Titer 16

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 HIV  Malaria  Tuberculosis  Cholera 18

 Safety  Sometimes illness follows vaccination ▪ Risk benefit analysis  Autism had been linked to vaccination ▪ Most recent studies conclude that there is no link but instead a genetic disposition  Weaning protection  Bordetella pertussis 19

 Patients antibodies  indicate that patient had contact with the agent before  “serology”  Commercial antibodies  used to detect patient antigen  In research  Detection of antigen  Purification 20

 Study of reactions between antibodies and antigens  Globulins  Serum proteins  Gamma (  ) globulin  Serum fraction containing Antibodies (immunoglobulin)  Antiserum  Generic term for serum when it contains specific Ab  Polyclonal  Monoclonal antibodies 21

 Prepare antigen  Inoculate animal with antigen and adjuvants  Administer several boosts  Draw blood and let it coagulate  Remove cells by centrifugation and collect supernatant = serum with high titers of specific antibodies 22

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 Precipitation  Agglutination  Hemagglutination  Fluorescent-antibody technique  ELISA 24

 Involve soluble antigens and antibodies  Upon cross linking a visible interlocking molecular aggregate is formed (lattice)  Only in equivalence zone precipitates are formed  Example  Ouchterlony 25

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 Involve particulate antigens and antibodies  IgM are most efficient  Direct agglutination  Antibodies against large cellular antigens  Indirect agglutination  Antibodies against soluble antigen adsorbed to a particle or erythrocytes 27

 Relates to the concentration of antibodies against a particular antigen  Gives a guide to how active the patient’s immune response is. 28

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To detect difficult to grow pathogens (e.g. Legionella) Labeled Specific Antibody 31

Figure 18.10b Specific Primary Antibody Labeled Secondary Antibody 32

To detect AgTo detect Ab 33

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 Vaccination (against disease) and immunizations (for antibody production) require administration of attenuated or inactivated antigen  Ab:Ag reaction is the fundamental reaction in immunology  Precipitation: ab--soluble ag  Agglutination: ab--particulate ag  Presence of antibodies does not mean illness  High titer means high concentration of ab 35

4) In an agglutination test, eight serial dilutions to determine antibody titer were set up: tube #1 contained a 1:2 dilution; tube #2, a 1:4, etc. If tube #6 is the last tube showing agglutination, what is the antibody titer? A) 6 B) 1:6 C) 64 D) 1:32 E) 32 16) A test used to identify antibodies against Treponema pallidum in a patient is the A) Direct fluorescent-antibody test. B) Indirect fluorescent-antibody test. C) Direct agglutination test. D) Direct ELISA test. E) Hemagglutination-inhibition test. 15) What type of vaccine is live measles virus? A) Conjugated vaccine B) Subunit vaccine C) Nucleic acid vaccine D) Attenuated whole-agent vaccine E) Toxoid vaccine 13) What type of vaccine involves host synthesis of viral antigens? A) Conjugated vaccine B) Subunit vaccine C) Nucleic acid vaccine D) Attenuated whole-agent vaccine E) Toxoid vaccine 36