Index
S.NO. Index Remark
1. Introduction
2. Types of immunity
3. Brief description of all
types
4. Mechanism
5. Vaccination
Definition
Types
Importance of
vaccination
6. Bibliography
INTRODUCTION
Immunity is the ability of the body to protect
against all types of foreign bodies like bacteria,
virus, toxic substances etc. which enter the body.
As it protects us from disease it is called disease
resistance.
Lack of immunity is known as susceptibility.
Immunity is done by immune system which is a
complex network of lymphoid organs such as bone
marrow, thymus, spleen etc.
Types of Immunity
Innate immunity
It is also called natural or native immunity, consist of
mechanism that exist before infection and are capable of
rapid responses to microbes.
It comprises of four types of defense barriers –
1. Anatomical barriers
2. Phagocytic barriers
3. Blood proteins and
4. Cytokines.
Types Mechanism
Skin Mechanical barriers retards entry of microbes.
Acidic environment retards growth of
microbes.
Mucous membrane Mucous entraps foreign microorganism.
Temperature Body temperature and fever response inhibits
. growth of some pathogens.
Low pH Acidic pH of stomach (pH 2) kills most
ingested . microorganism.
(Neutrophils, Macrophages and NK cells) Ingest and destroys microbes by endocytosis
and . phagocytosis) .
Tissue damage and infection induce leakage of
. vascular fluid, containing serum protein with antibacterial activity.
Types of innate immunity
Acquired immunity
Acquired or adaptive immunity is the immunity that is
developed by the host in its body after exposure to
suitable antigen or after transfer of antibodies or
lymphocyte from an immune donor.
Characteristics of Aquired Immunity
1. Antigenic Specificity
2. Diversity
3. Immunologic memory
4. Self/non-self recognition
Types of Acquired Immunity
Acquired Immunity is of two types- active and
passive immunity.
1. Active immunity
It is induced by natural exposure to a pathogen
or by vaccination.
It can be categorized into two types-
Naturally acquired and Artificially acquired
active immunity.
2. Passive immunity
Passive immunity is achieve by transfer of immune
products, such as antibody or sensitized T-cells,
from an immune individual to non immune one.
It is of two types- Naturally acquired and
Artificially acquired passive immunity
Mechanism of active immunity
Body's immune system provide protection by synthesizing
antibodies or immunoglobulins in response to an antigen.
Primary immune response takes place when the host is attacked
by certain microbes for first time. The antibodies start to
generate after certain period as the binding of an antigen with
its particular antibody is very specific.
Secondary immune response occurs when an individual is being
attacked by the same antigen subsequently. It is a rapid
process.
Acquired active immune response takes two distinct forms-
humoral and cell mediated response.
Passive Immunity
Passive immunity is provided when a person is given antibodies to a disease
rather than producing them through his or her own immune system.
A newborn baby acquires passive immunity from its mother through the
placenta.
People can also get passive immunity through antibody-containing blood
products such as immune globulin, which may be given when immediate
protection from a specific disease is needed.
The major advantage to passive immunity is that protection is immediate,
whereas active immunity takes time (usually several weeks) to develop.
However, passive immunity lasts only for a few weeks or months. Only
active immunity is long-lasting.
VACCINATION
Vaccination is a simple, safe, and effective way of protecting you
against harmful diseases, before you come into contact with
them. It uses your body’s natural defenses to build resistance to
specific infections and makes your immune system stronger.
Vaccines train your immune system to create antibodies, just as
it does when it’s exposed to a disease. However, because
vaccines contain only killed or weakened forms of germs like
viruses or bacteria, they do not cause the disease or put you at
risk of its complications.
TYPES OF VACCINE
Live-attenuated vaccines: They use a germ in a
weakened form.
Inactivated vaccines: They use a germ’s killed
version.
Subunit, recombinant, polysaccharide, and conjugate
vaccines: Such vaccines use only germ’s particular
pieces, like its casing, protein, and sugar.
Toxoid vaccines: Their preparation takes place
with a toxin made by the germ.
mRNA vaccines: Such vaccines use messenger RNA.
The messenger RNA provides instructions to the
cells for how to make a germ’s protein.
Viral vector vaccines: Such vaccines use genetic
material. They provide instructions to the cells for
making a germ’s protein.
Importance of vaccination
The following points demonstrate the importance of vaccination:
Saves lives: Experts recommend vaccines for infants due
to their underdeveloped immune systems. This way
vaccination help in protecting the lives of children.
Prevents dreadful diseases: Vaccines prevent illnesses
that are deadly in nature which can lead to severe
problems. For example, polio can lead to paralysis,
amputations, and may even prove fatal.
Saves money: The cure of diseases can be very costly.
Therefore, it is better to undertake vaccination before
contracting these diseases. This is better rather than going
through expensive medical treatment later on.
Vaccines are safe: All the vaccines today, generally
speaking, are reliable and safe for your child. In very rare
cases, there may be a side effect of a vaccine. The chances
of protection are much higher than in comparison to that of
a side effect.
Eradicates diseases: Vaccinations protect others besides
the ones getting the vaccines. With a proper vaccination
drive, a lot of deadly diseases will be eliminated in the
future. For example, vaccinated children can help protect
their siblings and friends from diseases.
Vaccines help in the long run: When vaccination takes
place, the immune system becomes really strong to fight
germs. This way, a person does not fall prey to diseases so
easily. Consequently, vaccination helps in the long run.
Bibliography
1. NCERT textbook of Biology
2. Website: www.google.com
3. www.scribd.com
4. www.slideshare.net
