From Wikipedia, the free encyclopedia Immunization
Immunization
immunogen in a controlled way, its body can learn to
protect itself: this is called active immunization.
The most important elements of the immune system
that are improved by immunization are the B cells (and
the antibodies they produce) and T cells. Memory B cell
and memory T cells are responsible for a swift response
to a second encounter with a foreign molecule. Passive
immunization is when these elements are introduced di-
rectly into the body, instead of when the body itself has
to make these elements.
Immunization is done through various techniques,
most commonly vaccination. Vaccines against microor-
ganisms that cause diseases can prepare the body’s im-
Dr. Schreiber of San Augustine giving a typhoid inoculation at mune system, thus helping to fight or prevent an infec-
a rural school, San Augustine County, Texas. Transfer from tion. The fact that mutations can cause cancer cells to
U.S. Office of War Information, 1944. produce proteins or other molecules that are unknown
to the body forms the theoretical basis for therapeutic
cancer vaccines. Other molecules can be used for immu-
nization as well, for example in experimental vaccines
against nicotine (NicVAX) or the hormone ghrelin (in ex-
periments to create an obesity vaccine).
Active immunization/vaccination has been named
one of the "Ten Great Public Health Achievements in the
20th Century".[1]
Passive and active immuniza-
tion
Immunization can be achieved in an active or passive
manner: vaccination is an active form of immunization.
Active immunization
Main article: Active immunity
Active immunization entails the introduction of a foreign
molecule into the body, which causes the body itself to
generate immunity against the target. This immunity
A child being immunized against polio. comes from the T cells and the B cells with their antibod-
ies.
Immunization or immunisation is the process by which
Immunization, immunisation, Active immunization can occur naturally when a per-
an individual’s immune system becomes fortified against son comes in contact with, for example, a microbe. If the
an agent (known as the immunogen). person has not yet come into contact with the microbe
When this system is exposed to molecules that are and has no pre-made antibodies for defense (like in pas-
foreign to the body (non-self), it will orchestrate an im- sive immunization), the person becomes immunized. The
mune response, but it can also develop the ability to immune system will eventually create antibodies and
quickly respond to a subsequent encounter (through im- other defenses against the microbe. The next time, the
munological memory). This is a function of the adaptive immune response against this microbe can be very effi-
immune system. Therefore, by exposing an animal to an cient; this is the case in many of the childhood infections
that a person only contracts once, but then is immune.
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From Wikipedia, the free encyclopedia Immunization
Artificial active immunization is where the microbe, outbreak of a particular disease or as an emergency treat-
or parts of it, are injected into the person before they are ment for toxicity (for example, for tetanus). The anti-
able to take it in naturally. If whole microbes are used, bodies can be produced in animals ("serum therapy") al-
they are pre-treated, Attenuated vaccine. though there is a high chance of anaphylactic shock be-
The importance of immunization is so great that the cause of immunity against animal serum itself. Thus, hu-
American Centers for Disease Control and Prevention has manized antibodies produced in vitro by cell culture are
named it one of the "Ten Great Public Health Achieve- used instead if available.
ments in the 20th Century".[1]
Passive immunization See also
Main article: Passive immunity • Immunization registry
Passive immunization is where pre-synthesized elements • Influenza vaccine
of the immune system are transferred to a person so that
the body does not need to produce these elements itself. References
Currently, antibodies can be used for passive immuniza-
[1] ^ "Ten Great Public Health Achievements in the
tion. This method of immunization begins to work very
20th Century". CDC
quickly, but it is short lasting, because the antibodies are
naturally broken down, and if there are no B cells to pro-
duce more antibodies, they will disappear. External links
Passive immunization occurs physiologically, when
• National Network for Immunization Information
antibodies are transferred from mother to fetus during
(NNii)
pregnancy, to protect the fetus before and shortly after
• Centers for Disease Control National Immunization
birth.
Program
Artificial passive immunization is normally adminis-
tered by injection and is used if there has been a recent
Retrieved from "http://en.wikipedia.org/w/index.php?title=Immunization&oldid=466649728"
Categories:
• Immunology
• Immune system
• Vaccination
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