Lippincott chapter 5 Flashcards
What is a vaccine?
A biological preparation that enhances immunity to a particular disease
What does the vaccine contain?
an agent that resembles a disease-causing microorganism and is often made of weakend or killed forms of the microbe, its toxins, or one of its surface proteins
Whooping cough =
Pertussis
German measles =
Rubella
Measles =
Rubeola
Chickenpox =
Varicella
Protection of individuals from disease by vaccination can take two forms:
- Passive immunization
- Active immunization
How is passive immunization achieved?
It is achieved by injecting a recipient with preformed immunoglobulins (Igs) obtained from human (or, occationally, equine(horsefamilies or horse)) serum.
What does the passive immunization provide?
It provides immediate protection to individuals who have been exposed to an infectious organism and who lack activie immunity to that pathogen
Does the passive immunization activate the immune system?
Nope. It generates no memory response
Dissipate =
dissapear or cause to dissapear
What happens with the passive immunization after getting inside the body?
Passive immunity dissipates after a few weeks to few months as the Igs are cleared from the recipient´s serum.
What two basic formulations of prepared Igs have been developed?
- from the serum of pooled human donors
- from serum obtained from hyperimmune donors
How is the active immunization achieved?
it is achieved by injection of viable or nonviable pathogens, or purified pathogen product, promting the immune system to respond as if the body were being attacked by an intact infectious microoorganism.
What does the passive immunization provide?
immediate protection
When does the active immunization provide effective protection?
Active immunization may require several days to months to become effective
What does the active immunization provide?
Active immunization leads to prolonged immunity and is generally preferred over the short-term immunity provided by passive immunization with preformed Igs.
Vaccines are:
- live, attenuated (weakened) microorganisms
- killed microorganisms
- microbial extracts
- vaccine conjugates
- inactivated toxins (toxoids)
Inactivated toxins =
Toxoids
Attenuated =
Weakened
Difference between killed microorganisms and live pathogens?
Killed vaccines have no risks compared to live pathogens, because the live pathogens that are weakened can become the active form.
Live pathogens:
- can become the active form (RISK)
- give long-lasting immune response
- should not be given to immunocompromised individuals because there is the potential fro a disseminated infection
Killed microorganism:
- no risk
- weak or short-lived immune response
Give example of vaccines that are available both in live and killed versions:
- polio vaccine
- typhoid vaccine
What are the microbial extracts vaccines composed of?
- composed of antigen molecules (instead of the whole organism) extracted from the pathogen or prepared by recombinant DNA techniques
Give example of how the efficiacy of the microbial extracts vaccines varies:
- vaccine antigen is present on all strains of the organisms, and the vaccine, thus, protects on all strains of the organism
- with e.g. pneumococcus, protective antibody is produced against only a specific capsular polysaccharide, one among more than 80 distinct types
What is the leading cause of the common cold?
rhino virus infection
Vaccine conjugates:
- vaccines can produce humoral immunity throught cell proliferation leading to antibody production, which may or may not involve helper T cells. Look at page 3 for examples
Toxoids:
- are derivatives of bacterial exotoxins produced by chemically altering the natural toxin or by engineering bacteria to produce harmless variants of the toxin
When are the vaccines containing toxoid used?
they are used when the pathogenicity of the organism is a result of secreted toxin. Depending on the specific vaccine, administration is generally via intramuscular or subcutaneous routes.
Give examples of vaccines containing killed pathogens:
- Hepatitis A
- Salk polio vaccine
Give examples of vaccines containing antigenic components of pathogens:
- Hepatitis B subunit vaccine
What types of vaccines elicit a primary B cell-mediated humoral response
Vaccines containing killed pathogens or antigenic components of pathogens do not enter host cells, thereby eliciting a primary B cell-mediated humoral response. These antibodies are ineffective in attacking intracellular organism.
How does a vaccine promote a cytotoxic T-cell response
.
