The
job of our immune system is protect us from getting sick (2). It protects us
from harmful substances, pathogens, and any changes in our cells (3). Our
bodies are made up with different organs and systems, for example the lymph
nodes. Our skin is the first layer of defense against any pathogen and serves
as a mechanical protective wall. Even our own saliva has enzymes that is able
to destroy the walls of some bacteria (4). The primary lymph organs, such as
the bone marrow, thymus, and thymus gland that are involved with the immunity
are responsible for controlling the production and maturation of our defense
cells called lymphocytes (4).
The
body’s immune system will become activated by different things that it does not
recognize, which are called antigens. Antigens can be proteins from the surface
of the bacteria, fungi, and viruses. Why they are become attached to special
receptors on immune cells a serious of processes are triggered. If the body has
not come into contact with that particular disease before then memory is
created so next time the body is able to fight it off faster (3).
There
are two types of immune, Innate (or non-specific) and adaptive immune system. The
innate immune system provides general defense against harmful germs and
substances. Its main job is to fight off disease. While the adaptive (or
specific) immunity will create antibodies and use these to fight off specific
disease that the body came into contact with previously (3). The adaptive can
be further subcategorized into active and passive immunity. Active immunity is
created by one’s own immune system when exposed to pathogen, either by the air
being breath in, the food eaten, or things touched. When our active immunity
fights off a pathogen it will create memory with B and T cells that are bale to
recognize a specific pathogen. Our memory cells are very important because they
allow our immune system to respond quickly and they have specificity. Meaning
they are specific for a single pathogen (2). Active immunity is long lasting
and often times lifelong. Vaccines will induce a person’s active immunity when
exposed to the pathogen (killed, weakened, or parts of it) through injection and
treat it as if it was like any regular infection and crates memory (1,2).
However, vaccines are developed as to not cause disease but still maintain the
benefit of exposure without the associated risks that is associated with the
natural infection (2).
Passive
immunity on the other hand is provided when a person is “give” antibodies to a
disease rather than producing them on their own through their own immune
system. Therefore, passive immunity only lasts for a few weeks or months and it
is not long lasting like active immunity. An example is a new born acquires
passive immunity form their mother through breast milk. The mothers breast milk
contains antibodies that protect the intestinal surface (immunoglobulin A or
IgA). Which is why in this period where a mother transfers her antibodies to
her baby is suggested at least until the baby’s immune system is able to
produce its own protection (1,2).
Resources:
- Centers for Disease Control and Prevention.
(2017, March 10). Vaccines: Vac-Gen/Immunity Types. Retrieved May 2, 2020, from
https://www.cdc.gov/vaccines/vac-gen/immunity-types.htm
- Children's Hospital of Philadelphia. (2019, April 16). Types of Immunity. Retrieved May 2, 2020, from https://www.chop.edu/centers-programs/vaccine-education-center/human-immune-system/types-immunity
- Institute for Quality and Efficiency in Health Care (IQWiG). (2019, November 07). How does the immune system work? Retrieved May 2, 2020, from https://www.ncbi.nlm.nih.gov/books/NBK279364/
- Institute for Quality and Efficiency in Health Care (IQWiG). (2016, January 20). What are the organs of the immune system? Retrieved May 2, 2020, from https://www.ncbi.nlm.nih.gov/books/NBK279395/
