Variolation is injection of human disease, makes person mildly sick. Higher risk than vaccines, sometimes serious illness occurs
Vaccination is an animal virus injected, usually no side effects
What is the difference between variolation and vaccination? Which is safer?
work because they stimulate the body to make antibodies against the pathogen
How do vaccines work?
Vaccines against enteric bacterial pathogens such as those causing cholera and typhoid are not as effective or longlived as those against viral disease polysaccharide components of outer surface (i.e. cell wall) do not stimulate production of effective antibodies as well as protein-coated viruses
Why do we often need "booster shots" when the vaccine is made of polysaccharide components?
were developed because of poor response to capsular polysaccharides (Children don't respond well to T-independent antigens until 15-24 years old) combines polysaccharide with toxoid
Hepatitis B vaccine is an example of this type of vaccine. ________ _____ are safe for immunocompromised patients because they cannot cause the disease.
vaccines which use only the parts of an organism yet which stimulate a strong immune response
problem with nucleic acid vaccine
Inject DNA, body makes protein and proteins acts as antigen. Problem is that DNA does not persist.
Ideal vaccine Cheap 1 shot gives lifetime immunity Doesn't need to be refrigerated Can be swallowed
What are the qualities of an "ideal" vaccine?
particulate - a cell Soluble- smaller materials
What is the difference between a soluble antigen and a particulate antigen?
precipitin ring test
Cloudy line appears in area in which optimal ratio has been reached (zone of equivalence)
This is used to look for "soluble" antigens IgM or IgG form large interlocking molecular aggregates called lattices
used to detect specific proteins in a given sample of tissue
Antigens may be on a cell or attached to latex spheres. Ex: slide agglutination
How can slide agglutination be used to detect the presence of antigens or antibodies?
a measurement of how much antibody an organism has produced that recognizes a particular epitope, expressed as the greatest dilution ratio (or its reciprocal) that still gives a positive result. ELISA is a common means of determining antibody titers
Antibody titer alone is of limited use in diagnosing an existing disease because the antibodies could be present from previous disease. Look for rise in titer or seroconversion
Why is antibody titer sometimes not helpful in determining present disease?
the reaction of an antibody with the antigen can be detected by agglutination (clumping) of the antigen
How is hemagglutination used to detect the presence of viral antibodies?
An antitoxin is an antibody with the ability to neutralize a specific toxin
Complement will combine (be fixed) with an antibody that is reacting with an antigen If all the complement is fixed in the complement-fixation stage, then none will remain to cause hemolysis of the RBC in the indicator stage
Describe how complement fixation can be used to indicate the presence of antibodies
Combine fluorescent dyes (ex: FITC) with antibody Quick, sensitive Direct FA usually used to detect microorganisms in a specimen
Describe fluorescent antibody identification of antigens or antibodies.
___________ is anti-human serum globulin (anti-HISG)
sort sperm into Y and X (female sperm has more DNA) used for couples that have genetic predisposition to X-linked disease.
What are some of the uses of the FACS technology?
Cells drop single file laser strikes and detector receives information Can also be used to sort cells according to charge Ex: sort sperm into Y and X (female sperm has more DNA) used for couples that have genetic predisposition to X-linked disease.
How does a flow cytometer work?
This procedure resembles that of the indirect FA test, except that the anti-HISG of the indirect assay is linked with an enzyme rather than a fluorescing dye Ex: first part of HIV testing
How does the indirect ELISA resemble the indirect FA test?
a. Ex: Salk polio vaccine
inactivated whole agent vaccine
viruses contain inactivated toxins Ex: tetanus and diphtheria vaccines Drawback is need for boosters
contain antigenic fragments Produced by genetic engineering techniques, i.e. other microbes are programmed to produce the desired antigenic fragment Ex: Hepatitis B vaccine produced in yeast
vaccines contain fractions of disrupted bacterial cell
Inoculation of smallpox into the skin usually results in a week of mild illness Occasionally causes serious disease This was commonplace in England in the 1700's. 1% mortality rate instead of 50% mortality
Suspension or organisms or fractions of organisms (antigens) that is used to induce immunity is often the only way of controlling viral illness work because they stimulate the body to make antibodies against the pathogen
results when most of the population is immune to a disease even though everyone may not have been vaccinated
attenuated whole agent
_____________are living but weakened microbes. Effective, life-long immunity these viruses replicate in the body and new Viruse act as secondary ("booster") immunization. Danger is that live microbes can mutate back to virulent form. Ex: MMR, Sabin polio
Western blot of antibodies Separate protein, then immunoblot
involves particulate antigens and antibodies (i.e. a cell) Antigens may be on a cell or attached to latex spheres.
concentration of antibodies against a particular antigen. For infectious diseases in general, the higher the serum antibody titer, the greater the immunity
the development of detectable specific antibodies to microorganisms in the blood serum as a result of infection or immunization
______________involves agglutination of RBC Used for blood typing
Enzyme-linked Immunosorbent Assay) Direct method detects antigens Visible because second antibody is linked to an enzyme when substrate is added, there is a color change Ex: urine test for drugs
What blotting technique uses the following for analysis? • Protein
What is the confirmatory test for HIV?
________contain fractions of disrupted bacterial cell
inactivated whole agent vaccine
EX: salk polio
viruses that have the ability to agglutinate RBC without an antigen-antibody reaction
used to indicate the presence of antibodies to a known antigen
if the antibody is present in complement fixation, there will be
lysis of the cell
if the antibody is absent in complement fixation, there will be
direct Fluorescent antibody technique (FA)
usually used to detect microorganisms in a specimen
used to detect a specific antibody in serum following exposure
2nd antibody is anti-human
direct method of ELISA detects
indirect method of ELISA detects
Agglutination (particulate antigens) Hemagglutination (RBC) precipitation (soluble antigens) Compliment fixation (RBC's are indicator) Neutralization (inactivates toxins) ELISA (peroxidase enzyme is the indictator)
serological tests (7)
protects against diphtheria, pertussis and tetanus