Flashcards in Immunization Deck (28):
What is immunization?
rendering a person protected from an infectious disease
How does an immunization work?
-Can occur naturally by having this disease once-giving the immune system a memory of the disease
-once immunized if ever see antigen again get a more powerful, faster, adaptive immune response and don't become clinically ill
Two ways to induce/provide immunity to specific diseases
Passive immunity definition
transfer of active humoral immunity in the form of ready made antibodies from one individual to another
How can passive immunity occur naturally?
when maternal antibodies are transferred to fetus through placenta & breastfeeding
How can passive immunity be induced artificially
high levels of human (or horse) Abs specific for a pathogen or toxin are transferred to non-immune individuals (used to counteract effect of a toxin)
when is passive immunization used?
when there is a high risk of infection and insufficient time for the body to develop its own immune response or to reduce the sx of ongoing or immunosuppressive disease
How is passive immunity provided?
by giving preformed IgG Abs specific for the disease state trying to prevent
pros of passive immunization
works faster than active and protects during incubation period (give when not enough time for vaccine to work before disease starts)
cons of passive immunity
-is short term--gone when Immunoglobulin is gone
-if get exposed again and immunoglobulin is gone, you can get the disease
(it's not as effective as actively immunizing)
How is disease specific IgG prepared?
by exposing humans or animals to the disease, then harvesting the Abs they make in response
Why is human immunoglobulin preferred
fewer rxns & last about 3wks
animal immunoglobulin is used when....
What do you need to do with it?
animal used if you can't get human
-it has more runs & doesn't last as long as human
-need to test for hypersensitivity first b/c many allergic runs
What type of animal Ig causes least number of reactions
IgG available from horse source
(for which diseases)
diseases IgG are available for
Active immunization definition
induction of immunity after exposure to an antigen
how does active immunization work?
-Abs created by recipient and may be stored permanently
-usually series of injections/exposures over period of time
-large part of primary care
-not all that receive vaccination are immune
What are Live attenuated vaccines
weakened form of pathogen which replicates after administration to induce an immune response
-most viral vaccines invoke the use of live virus that has been chemically changed to decrease virulence (so it doesn't cause serious disease in people & so immune response is more like having disease)
Benefit of live attenuated vaccines
-immune response is more like having the disease
-usually get a superior response and typically doesn't require multiple doses
-often only need one dose (maybe 2) for lifelong immunity
weakened toxins are called...
toxoid vaccines prevent
disease caused by bacteria that produce toxins
often toxoids are combined with_____ to prolong absorption
Examples of live attenuated vaccines
-measles, mumps, rubella
How are killed, inactivated vaccines made and what are they prepared from?
made by inactivating/killing the virus
-prepared from whole bacteria/virus or fractional antigenic component of one
Examples of Killed vaccines
bacteria have antigens with outer coating of polysaccharides
-conjugate vaccines conjugate the polysachs to antigens that the immune system responds to well