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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?

1. attenuated whole agent
2. inactivated whole agent
3. toxoid
4. subunit
5. acellular
6. conjugated

the 6 types of vaccines

Conjugated vaccine

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

subunit vaccines

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

Western blot

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?

antibody titer

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?

anti-toxin

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.

secondary antibody

___________ 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

toxoid vaccine

subunit vaccine

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

acellular vaccine

vaccines contain fractions of disrupted bacterial
cell

Variolation

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

vaccination

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

herd immunity

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

immunoelectrophoresis

Western blot of antibodies
Separate protein, then immunoblot

agglutination

involves particulate antigens and antibodies (i.e. a cell)
Antigens may be on a cell or attached to latex spheres.

titer

concentration of antibodies against a particular antigen. For infectious diseases in general, the higher the serum antibody titer, the greater the immunity

seroconversion

the development of detectable specific antibodies to microorganisms in the blood serum as a result of infection or immunization

hemagglutination

______________involves agglutination of RBC
Used for blood typing

ELISA

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

western blot

What blotting technique uses the following for analysis? • Protein

What is the confirmatory test for HIV?

acellular vaccines

________contain fractions of disrupted bacterial cell

inactivated whole agent vaccine

EX: salk polio

viral agglutination

viruses that have the ability to agglutinate RBC without an antigen-antibody reaction

complement fixation

used to indicate the presence of antibodies to a known antigen

no lysis

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

indirect FA

used to detect a specific antibody in serum following exposure

2nd antibody is anti-human

antigens

direct method of ELISA detects

antibodies

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)

dTap

protects against diphtheria, pertussis and tetanus

haemophilus influenza

type B meningitis vaccine

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