The document discusses immunization and the immune system. It begins by thanking teachers for providing an opportunity to study immunization. It then provides 3 paragraphs summarizing key aspects of immunization: it stimulates the body's immune system to protect against infection through vaccination; it provides long-lasting immunity through immune system memory; and it harnesses this memory to provide quicker protection if the pathogen is encountered again. The document emphasizes that immunization is a safe and effective way to protect individuals and communities from serious diseases.

1. By :- jyoti pandey

2. Acknowledgement :-
I would like to express my special thanks of gratitude
to my teacher (Dr. Sufiya Khan mam) who gave me
the golden opportunity to do this wonderful project
on the topic (germ immunization ), which also
helped me in doing a lot of Research and i came to
know about so many new things I am really thankful
to them.
Secondly i would also like to thank my parents and
friends who helped me a lot in finalizing this project
within the limited time frame.
Jyoti Pandey
Bsc . Biotechnology 4th sem

3. Germ Immunization :-
Immunization is the process whereby a person is made
immune or resistant to an infectious disease, typically
by the administration of a vaccine. Vaccines stimulate
the body's own immune system to protect the person
against subsequent infection or disease.
Immunisation describes the process whereby people
are protected against illness caused by infection with
micro-organisms (formally called pathogens).
The term vaccine refers to the material used for
immunisation, while vaccination refers to the act of
giving a vaccine to a person.
Immunity describes the state of protection that
occurs when a person has been vaccinated or has
had an infection and recovered.

4. Vaccination, like infection, confers immunity by
interaction with the immune system.
The term micro-organism refers to infectious agents
that can only been seen under the microscope and
here covers bacteria, viruses, fungi and protozoa.
Antigens are the components/fragmentsfrom
pathogens or their toxins.

5. Immunisation is disease-specific:-
A healthy immune system has the capacity to
generate hundreds of millions of T- and B-cells, each
of which targets one particular antigen.
Consequently, healthy people have the capacity to

6. mount a protective response to essentially every
infection they could possibly encounter during their
lifetimes .
However, pathogens have evolved to overcome this
defence and can sometimes overwhelm the immune
response. Vaccines give the immune system a head
start, providing valuable early protection against
aggressive pathogens.
The specificity of these immune responses is the
reason we need to have a separate vaccine for each
disease. The capacity of the immune system to
respond independently to each micro-organism in
the environment also explains why the system
cannot be ‘overloaded’ or damaged by giving the full
range of currently available vaccines or by having
multiple antigens in one vaccine preparation.

7. Vaccines harness the immune
system’s capacity for memory:-
When a pathogen is recognised by the immune system,
individual lymphocytes not only make antibodies and
cytokines against the infection, but also multiply quickly.

8. As a result, the number of lymphocytes (T- and B-cells)
specific for that infection increases greatly, enabling the
body to fight the infection more efficiently. Most of the
cells involved in immune responses live for only a few
days as effector cells, but a small number of
lymphocytes survive for months or years after the
infection has been cleared and retain a ‘memory’ of the
invading pathogen . In the case of measles, for example,
that memory has been shown to last for more than 60
years.
The immune system’s memory of infections it has been
exposed to previously is one of its most valuable assets.
This memory means the immune system is ready to
mount a much quicker, larger and more sustained
response if it encounters the same pathogen again (see
Figure 1.2).
That response can control subsequent infection more
efficiently, without leading to the unwanted and serious
complications that can be associated with infection in
non-immune people (see Box 2).

10. What Is the Immune System?
The immune system is the body's defense against
infections. The immune (ih-MYOON) system attacks
germs and helps keep us healthy.
What Are the Parts of the
Immune System?
Many cells and organs work together to protect the
body. White blood cells, also called leukocytes (LOO-
kuh-sytes), play an important role in the immune
system.
Some types of white blood cells,
called phagocytes (FAH-guh-sytes),chew up
invading organisms. Others,
called lymphocytes (LIM-fuh-sytes), help the body
remember the invaders and destroy them.
One type of phagocyte is the neutrophil (NOO-truh-
fil), which fights bacteria. When someone might
have bacterial infection, doctors can order a blood
test to see if it caused the body to have lots of

11. neutrophils. Other types of phagocytes do their own
jobs to make sure that the body responds to
invaders.
The two kinds of lymphocytes are B
lymphocytes and T lymphocytes. Lymphocytes start
out in the bone marrow and either stay there and
mature into B cells, or go to the thymus gland to
mature into T cells. B lymphocytes are like the
body's military intelligence system — they find their
targets and send defenses to lock onto them. T cells
are like the soldiers — they destroy the invaders
that the intelligence system finds.
How Does the Immune System
Work?
When the body senses foreign substances (called
antigens), the immune system works to recognize
the antigens and get rid of them.
B lymphocytes are triggered to make antibodies.
These specialized proteins lock onto specific

12. antigens. The antibodies stay in a person's body.
That way, if the immune system encounters that
antigen again, the antibodies are ready to do their
job. That's why someone who gets sick with a
disease, like chickenpox, usually won't get sick from
it again.
This is also how immunizations (vaccines) prevent
some diseases. An immunization introduces the
body to an antigen in a way that doesn't make
someone sick. But it does let the body make
antibodies that will protect the person from future
attack by the germ.
Although antibodies can recognize an antigen and
lock onto it, they can't destroy it without help. That's
the job of the T cells. They destroy antigens tagged
by antibodies or cells that are infected or somehow
changed. (Some T cells are actually called "killer
cells.") T cells also help signal other cells (like
phagocytes) to do their jobs.
Antibodies also can:

13.  neutralize toxins (poisonous or damaging
substances) produced by different organisms
 activate a group of proteins called complement that
are part of the immune system. Complement helps
kill bacteria, viruses, or infected cells.
These specialized cells and parts of the immune
system offer the body protection against disease.
This protection is called immunity.
Humans have three types of immunity — innate,
adaptive, and passive:
 Innate immunity: Everyone is born with innate (or
natural) immunity, a type of general protection. For
example, the skin acts as a barrier to block germs
from entering the body. And the immune system
recognizes when certain invaders are foreign and
could be dangerous.
 Adaptive immunity: Adaptive (or active)
immunity develops throughout our lives. We
develop adaptive immunity when we're exposed to
diseases or when we're immunized against them
with vaccines.

14.  Passive immunity: Passive immunity is
"borrowed" from another source and it lasts for a
short time. For example, antibodies in a mother's
breast milk give a baby temporary immunity to
diseases the mother has been exposed to.
The immune system takes a while to develop and
needs help from vaccines. By getting all your
child's recommended vaccines on time, you can help
keep your child as healthy as possible.

15. Which Immunizations Do My
Children Need?
Because proof of immunization is often a prerequisite
forenrollment in schoolor day care, it's important to
keep your children up to date on their vaccines. The
benefit of doing so is that your children will be protected
from diseases that could cause themserious health
problems. The recommendedimmunizations for
children 0-6years of age include:
 Hepatitis B
 Rotavirus
 Diphtheria, tetanus, pertussis
 Haemophilus influenzae type B
 Pneumococcal
 Poliovirus
 Influenza
 Measles, mumps,rubella
 Varicella (chickenpox)
 Hepatitis A

16.  Meningococcal (forcertain high-risk groups)
At one time or another, each of the diseases addressed
by thesevaccines poseda serious health threat to
children, taking their lives by the thousands;today most
of these diseasesare at theirlowest levels in decades,
thanksto immunizations.
Benefits of immunisation:-
Immunisation is a simple and effective way of
protecting yourself and your family.
Immunisation works by triggering the immune
system to fight against certain diseases. If a
vaccinated person comes in contact with these
diseases, their immune system is able to respond
more effectively. This either prevents the disease
from developing or reduces the severity.
Immunisation not only protects your own family, but
also others by helping to control serious diseases in
our community.

17. Immunisation is a very safe
prevention tool:-
All vaccines used in Australia must be approved
for use by the Therapeutic Goods
Administration (TGA), who monitors the safety
of medicines in Australia. Before a vaccine can
be licensed, it is rigorously tested over several
years to ensure it is safe and that it works.

18. Reference :-
www.biologydiscussion.com
www.webmd.com
www.helthengin.com
www.kidshealths.org
www.science.org