This document discusses different types of immunity. It describes innate immunity, which is non-specific and provides immediate protection. Adaptive immunity is specific and takes time to develop, providing long-term protection through active natural or artificial immunity, as well as passive natural or artificial immunity. Community immunity is achieved when a sufficient portion of a population is immune, indirectly protecting those who are not.

1. IMMUNITY
NURSING LIBRARY

2. INTRODUCTION
 Immunity to a disease is achieved through the presence of antibodies to that disease in a
person’s system.
 Antibodies are proteins produced by the body to neutralize or destroy toxins or disease-carrying
organisms.
 Antibodies are disease-specific. For example, measles antibody will protect a person who is
exposed to measles disease, but will have no effect if he or she is exposed to mumps.
NURSING LIBRARY

3. IMMUNITY
The ability of an organism to resist a particular infection or toxin
by the action of specific antibodies or sensitized white blood
cells.

4. Terminologies
Immunization:Immunization, or immunisation, is the process by which
an individual's immune system becomes fortified against an agent
Vaccine:A vaccine is a biological preparation that provides active
acquired immunity to a particular infectious disease.Vaccines contain a
contain a microorganism or virus in a weakened, live or killed state, or
state, or proteins or toxins from the organism.
Vaccination:Vaccination is the administration of a vaccine to help the
immune system develop protection from a disease.

5. Seroprotection refers to the state of protection
disease,due to the presence of detectable
levels of antibody.

6. Immunogenicity is the ability of a vaccine to elicit an
immune response, whether cellular, humoral or both.
Adjuvants are substances unrelated to the organism that,
when added to a vaccine, enhance its immunogenicity.
Protective efficacy is the vaccine's actual ability to protect
against disease.

7. IMMUNITY
Innate
Adaptive
(acquired)
Active
Natural
Artificial
Passive
Natural
Artificial
Community
(herd)

8. INNATE OR NATIVE IMMUNITY
 Innate or native immunity is acquired by birth through the genes.
 It is a more general or nonspecific component of the immune system- i.e., it attacks
any germs that threaten the body.
 The innate component of the immune system mounts an immune response
immediately or within a few hours of entry of the pathogen.
 It is not affected by prior contact with micro organisms and immunization

9. COMPONENTS OF INNATE IMMUNITY
External component –
This is the first line of defense, acting as a barrier
to prevent entry of pathogens into the body.
Eg: skin, mucous membranes and stomach acid.
Internal component - This is the second
line of defense which fights pathogens
once they have entered the body.
This includes mechanisms like fever,
inflammation and phagocytosis (a process
by which macrophages and natural killer
cells of our body engulf the germs and kill
them)

10. LEVELS OF INNATE IMMUNITY
Species immunity
Racial immunity
Individual immunity

11. Species immunity
Total or relative resistance to pathogen, shown by all
members of the species
Eg: All human beings are resistant to plant pathogens
and many animal pathogens

12. Racial immunity
Different races within same species may show differences
in susceptibility to infection
Eg: Genetic resistance to plasmodium falciparum in some
parts of Africa

13. Individual immunity
Different immunity exhibited by different individual
in race

14. 2. ADAPTIVE (ACQUIRED) IMMUNITY
The adaptive immune system is specific, i.e. it targets a specific
pathogen and takes some time to develop. It also provides long-
term immunity from the specific pathogen

15. 2.A ACTIVE ADAPTIVE IMMUNITY
 Due to the exposure to pathogens, your body develops B-cells and T-
cells.
 These cells clear the existing germs through humoral immunity
(antibody) or cell mediated immunity.
 Additionally, they also form memory B-cells and T-cells that can
quickly respond to future infections. Active acquired immunity can be
natural or artificial.

16. Active adaptive
(acquired)
immunity
Natural:
 When a person has been naturally exposed to the pathogen due to infection,
antibodies are produced that fight off the pathogen.
 Memory cells are formed to mount a quicker response in case of re-
infection.
Artificial
• When the infection is created artificially in a controlled manner, the acquired
immunity is known to be artificial in nature. This is seen in the case of
vaccination.
• During vaccination, a dead or inactivated germ, its proteins (antigens) or
toxins are injected into the body.

17. 2.B passive acquired immunity
When readymade antibodies are provided to the body to fight off a particular infection,
it is known as passive acquired immunity. This gives immediate protection from a
specific infection. It is usually given to high-risk patients or to patients with
immunodeficiency (cannot make their own antibodies).

18. Passive Acquired Immunity
NATURAL
In natural passive immunity, certain antibodies
from the mother’s body reach the foetus
through the placenta.
Other antibodies are passed on to the child
through breast milk. These antibodies provide
protection to the newborn
ARTIFICIAL
Here, readymade antibodies, specific to the disease,
are introduced into the vulnerable person’s
bloodstream to defend against infection.
These antibodies are acquired from a previously
infected person, or are produced in another
organism.

19. 3. COMMUNITY OR HERD IMMUNITY
This is an indirect form of immunity. When enough members of a
particular community or region are immune to a specific disease (due to
vaccination or prior illness), the members not immune to the disease are
also protected. This happens due to breaking of the ‘chain of infection’,
whereby the disease causing pathogen cannot spread, because most
people are resistant to this pathogen.