Download The Immune System

The Immune System
(Part 2)
Interferon
Certain cells infected with a virus release a
substance that prevents the cells nearby
from producing more virus.
 It is called interferon because it interferes
with the spread of the virus
 Interferons are now being produced for
treatment by genetic engineering in
microorganisms
 They are used to treat viral infections like
hepatitis and have been used to boost the
immune response to certain kinds of
cancers

Types of Immunity

Innate Immunity – is inborn and is
inherited along with other characteristics
in a person’s genes.
Types of Immunity

Adaptive Immunity – develops after birth
and can be acquired by natural or artificial
means
Natural Adaptive Immunity (Active)

When the body is exposed to a specific
disease organism where the person’s body
makes antibodies against the infectious
agent.
Chicken Pox
Natural Adaptive Immunity (Passive)
Immunity acquired by the passage of
antibodies from mother to her fetus
through the placenta or through breast
milk during nursing.
 This immunity only lasts about 6 months

Artificial Adaptive Immunity

Immunization or vaccination – when a
weakened or dead organism is cultured
and then injected into the body. The
body’s immune response will be to make
antibodies against the specific organism
giving the person immunity against the
disease.
Antibody Formation
Immunization Boosters
In many cases, acquired immunity does
not last a life-time because the level of the
specific antibodies can decrease over time
 To maintain higher levels of these
antibodies, there may be a need for
additional immunization for the disease
(example: measles, mumps, rubella –
given at 15 mons and again at ages 4-6yrs)
