Chapter 18

Vaccine History

jenner inoculated cowpox to prevent smallpox, termed vaccination by Pasteur

vacca = cow

Vaccine

suspension of organisms or fractions of organisms that induce immunity (T cell and B cell response)

naturally made, but artificially produced, we want most IgG

Effects of Vaccination

provokes a primary immune response (formation of antibodies and memory cells)

produces a rapid, intense secondary response (no delay bc of memory cells)

Herd Immunity

immunity in most of the population

outbreaks are sporadic due to the lack of susceptible individuals

Live attenuated vaccines

weakened pathogen (heat treat, pressure)

closely mimic an actual infection

confers lifelong cellular(T cell) and humoral (B cell) immunity

Ex. flu mist given to ONLY HEALTHY ADULTS

Inactivated killed vaccines

safer than live vaccines bc no chance to get the disease

requires repeated booster doses

induce mostly humoral immunity

Ex. 1, Dtap 2. Trap (booster)

Conjugated vaccines

extra proteins added to bulk up vaccine

used for diseases in children with poor immune response to capsular polysaccharides

successful vaccine for Haemophilus incluenzae type B

Diagnostic Immunology

find ID of bacteria right away

Sensitivity

probability that the test is reactive is the specimen is a true positive

Ex. gram testing is not sensitive bc you need a lot of bacteria for a good result

Specificity

probability that a positive test will not be reactive if a specimen is a true negative

Ex. an antibody test for all types of viruses, not specific bc it will react to anything

Immunologic-based diagnostic tests

interactions of humoral antibodies with antigens

known antibody can identify an unknown pathogen

known pathogen can identify an unknown antibody

Hybridoma

immortal cancerous B cell (myeloma) combined with an antibody producing normal B cell

produces Mabs

add PEG to chemically bind them together

Monoclonal antibodies (mabs)

stay forever, produced by hybridoma

uniform, highly specific, and produced in large quantities

Mabs in clinical

used in diagnostic tools and human therapy

treat allergic asthma (no IgE binding) and neutralize TNF with arthritis

often derived from mouse cells, leading to side effects

Production of Mabs steps

1. mouse injected with antigen so antibodies are produced

2. spleen of mouse removes and suspended

3. spleen cells mixed with myeloma cells so they can continuously grow, while still producing antibodies

4. mixture of cell placed in selective medium so only hybrid cells grow

5. hybrid cells proliferate into clones called hybridomas

6. these are isolated and mass produced for diseases

Fluorescent antibody

helps with ID testing

bacteria combined with antibodies first(indirect) or straight florescent antibodies(direct)

Pregnancy test

specificity is good, sensitivity is not

monoclonal antibody specific for hCG and capture monoclonal antibody bound, form a sandwich when hCG is present, and there is color change

Direct ELISA

1. antibody is adsorbed to well

2. patient sample added, antigen binds with antibody

3. enzyme linked antibody is added, and binds to antigen forming sandwich

4. enzymes substrate is added, and reaction produces a product that changes color

Indirect ELISA

1. antigen is absorbed to well

2. patient serum is added, antibody binds to antigen

3. enzyme linked anti HISG is added and binds with bound antibody

4. enzyme’s substrate is added, and reaction causes a color change