This document provides an introduction to immunization. It discusses the history of immunization beginning with Edward Jenner's smallpox vaccine in 1796. It describes active immunization which involves administration of antigens to induce an immune response, and passive immunization which involves transfer of pre-formed antibodies. Common childhood vaccines and booster shots are listed. Benefits of immunization include disease protection while risks include mild side effects. Various antibody-antigen tests used in immunology are also summarized such as precipitation, agglutination, neutralization, and ELISA tests.

1. INTRODUCTION TO
IMMUNIZATION
2013-14
2013-14
VIKAS SONI
Management Scholar,
Pharmaceutical Management,
NIPER, Mohali, Punjab, India.
GMAIL: Vikas.niper2014@gmail.com
LINKEDIN: http://in.linkedin.com/in/vikassoni11/
FACEBOOK: https://www.facebook.com/Vickysoni11

2. INTRODUCTION TO IMMUNIZATION
1. INTRODUCTION
2. HISTORY
3. IMMUNIZATION AND BOOSTER SHOTS
4. BENEFITS OF IMMUNIZATION
5. SIDE EFFECTS OF IMMUNIZATION
6. CLASSIFICATION OF IMMUNIZATION
7. ACTIVE IMMUNIZATION
8. PASSIVE IMMUNIZATION
9. ANTIBODY ANTIGEN IMMUNE TESTING:
 Precipitation Tests.
 Agglutination Tests.
 Neutralization Tests.
 The Complement Fixation Test.
 Labeled Antibody Test.
10. RECENT DEVELOPMENTS
11. REFERENCES
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3. INTRODUCTION TO IMMUNIZATION
INTRODUCTION:
Immunization is the process by which an individual's immune system becomes fortified
against an agent (known as the immunogen). When this system is exposed to molecules
that are foreign to the body, called non-self, it will orchestrate an immune response, and it
will also develop the ability to quickly respond to a subsequent encounter because of
immunological memory. This is a function of the adaptive immune system. Therefore, by
exposing an animal to an immunogen in a controlled way, its body can learn to protect
itself, this is called active immunization. Immunization is done through various
techniques, most commonly vaccination. Vaccines against microorganisms that cause
diseases can prepare the body's immune system, thus helping to fight or prevent an
infection. Before the introduction of vaccines, the only way people became immune to an
infectious disease was by actually getting the disease and surviving it. Smallpox (variola)
was prevented in this way by inoculation, which produced a milder effect than the natural
disease. Immunizations are definitely less risky and an easier way to become immune to a
particular disease than risking a milder form of the disease itself. They are important for
both adults and children in that they can protect us from the many diseases out there.
Through the use of immunizations, some infections and diseases have almost completely
been eradicated throughout the World.
HISTORY:
Since the time of the ancient Greeks, it has been recognized that people who have
recovered from plague, smallpox, yellow fever, and various other infectious diseases rarely
contract the diseases again. The first scientific attempts at artificial immunizations were
made in the late eighteenth century by Edward Jenner (1749–1823): a country doctor
from Berkley, Gloucestershire, England. Jenner investigated the basis for the widespread
belief of the English peasants that anyone who had vaccinia (cowpox) never contracted
smallpox. Smallpox was often fatal—10 to 40% of the victims died—and those who
recovered had disfiguring pockmarks. Yet most English milkmaids, who were readily
infected with cowpox, had clear skin because cowpox was a relatively mild infection that
left no scars. It was on May 14, 1796, that Jenner extracted the contents of a pustule from
the arm of a cowpox-infected milkmaid, Sarah Nelmes, and injected it into the arm of
eight year old James Phipps. As Jenner expected, immunization with the cowpox virus
caused only mild symptoms in the boy. When he subsequently inoculated the boy with
smallpox virus, the boy showed no symptoms of the disease. Jenner then inoculated large
numbers of his patients with cowpox pus, as did other physicians in England and on the
European continent. By 1800 the practice known as vaccination had begun in America,
and by 1805 Napoleon Bonaparte had ordered all French soldiers to be vaccinated.
Further work on immunization was carried out by Louis Pasteur (1822–1895). Pasteur
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4. INTRODUCTION TO IMMUNIZATION
discovered that if cultures of chicken cholera bacteria were allowed to age for two or three
months the bacteria produced only a mild attack of cholera when inoculated into
chickens. Somehow the old cultures had become less pathogenic (attenuated) for the
chickens. He then found that fresh cultures of the bacteria failed to produce cholera in
chickens that had been previously inoculated with old, attenuated cultures. To honor
Jenner’s work with cowpox, Pasteur gave the name vaccine to any preparation of a
weakened pathogen that was used (as was Jenner’s “vaccine virus”) to immunize against
infectious disease.
IMMUNIZATION AND BOOSTER SHOTS:
The childhood immunization schedule outlines the following immunizations and booster
shots and these include:
● Diphtheria, tetanus, and pertussis (also known as whooping cough)
● Measles, mumps, and rubella
● Chickenpox
● Polio
● Hepatitis B
● Hepatitis A
● Rotavirus
● Bacterial meningitis
● Human papilloma virus (HPV)
● Haemophilus influenzae type b disease
● Pneumococcal disease
● Flu (influenza)
BENEFITS OF IMMUNIZATION:
Immunizations have a number of benefits and these include:
 Protects against certain diseases.
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5. INTRODUCTION TO IMMUNIZATION
 Helps the immune system build resistance against disease.
 Minimizes the spread of disease to others and prevents epidemics.
 Cost effective way of getting treated for diseases.
 Often required for entrance into daycare facilities, school, college, employment or
travel to another country.
 In pregnancy periods, it is necessary that the vaccinations are up to date to protect
the baby.
 Fewer side effects.
SIDE EFFECTS OF IMMUNIZATION:
There can be side effects from immunizations as it entails injecting a virus into body. If
serious side effects such as,
 Severe allergic reactions.
 Difficulty breathing.
 Fever over 104.5F.
 Common reactions that may occur include:
 Mild pain.
 Swelling, soreness or redness on the area where the injection was given.
 Muscle ache or joint pain after a measles-mumps-rubella shot.
 Mild rash after chickenpox or measles-mumps-rubella shots for about 7 to 14 days.
 Slight fever.
 Fussiness (often seen in babies).
 Loss of appetite.
 It is important to consult with health practitioner immediately.
CLASSIFICATION OF IMMUNIZATION:
Two Artificial Methods of Immunity,
1. Active immunization:
Administration of antigens so patient actively mounts a protective immune response
2. Passive immunization:
Individual acquires immunity through the transfer of antibodies formed by immune
individual or animal.
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6. INTRODUCTION TO IMMUNIZATION
ACTIVE IMMUNIZATION:
 DEFINITION:
It is the protection of susceptible humans and domestic animals from communicable diseases by
the administration of vaccines (vaccination). A vaccine [Latin vacca, cow] is a preparation from
an infectious agent that is administered to humans and other animals to induce protective
immunity. It may consist of a preparation of killed microorganisms; living, weakened (attenuated)
microorganisms; inactivated bacterial toxins (toxoids); purified macromolecules; recombinant
vectors (e.g., modified polio vaccine); or DNA vaccines that are administered to an animal to
induce immunity artificially.
 HISTORY:
The modern era of vaccines and vaccination began in 1798 with Edward Jenner’s use of cowpox as
a vaccine against smallpox and in 1881 with Louis Pasteur’s anthrax vaccine. Vaccines for other
diseases did not emerge until the latter part of the nineteenth century, when largely through a
process of trial and error, methods for inactivating and attenuating microorganisms were
developed and vaccines were produced. Vaccines were eventually developed against most of the
epidemic diseases that had plagued Western Europe and North America (diphtheria, measles,
mumps, whooping cough, German measles, polio). Indeed, toward the end of the twentieth
century it began to seem that the combination of vaccines and antibiotics would temper the
problem of microbial infections. Such optimism was cut short by the emergence of new or
previously unrecognized diseases and antibiotic resistance to old ones. Nevertheless, vaccination
is still one of the most cost-effective weapons for microbial disease prevention.
1. VACCINE TYPES:
1. Combination vaccines:
 Administration of antigens from several pathogens.
2. Vaccines using recombinant gene technology:
 Attempts to make vaccines more effective, cheaper, safer.
 Variety of techniques used to improve vaccines.
2. Vaccine manufacture:
 Mass-produce many vaccines by growing microbes in culture vessels.
 Viruses are cultured inside chicken eggs.
 Individuals with egg allergies must avoid some vaccines.
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7. INTRODUCTION TO IMMUNIZATION
3. Vaccine safety:
 Problems associated with immunization
 Mild toxicity most common.
 Risk of anaphylactic shock.
 Residual virulence from attenuated viruses.
 Allegations that certain vaccines cause autism, diabetes, and asthma.
 Research has not substantiated these allegations.
 EXAMPLES:
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8. INTRODUCTION TO IMMUNIZATION
PASSIVE IMMUNIZATION:
 DEFINITION:
Artificially acquired passive immunity can be produced by injecting an animal or human
with preformed antibodies that have been produced in another animal, in another human,
or in vitro. This type of immunization is called passive because protection does not
require participation of the recipient’s immune system. Passive immunization is routinely
administered to individuals exposed to certain microbial pathogens that cause diseases
such as botulism, diphtheria, hepatitis, measles, rabies, and tetanus as well as to protect
them against snake and spider bites. However, this form of immunization should be used
only when absolutely necessary because of the risks involved such as developing
anaphylaxis, serum sickness, or a type III hypersensitivity reaction. Furthermore, the
protection lasts only as long as the antibody molecules survive in the recipient—months
with antibodies from another human, but only weeks with antibodies from animals or in
vitro methods.
Antisera have several limitations:
 Contain antibodies against many antigens.
 Can trigger allergic reactions called serum sickness.
 Viral pathogens may contaminate antisera.
 Antibodies of antisera are degraded relatively quickly.
 Limitations are overcome through development of hybridomas.
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9. INTRODUCTION TO IMMUNIZATION
 COMPARISON OF INACTIVATED (KILLED) AND
ATTENUATED (LIVE) VACCINES:
ANTIBODY ANTIGEN IMMUNE TESTING:
Serology: Study and diagnostic use of antigenantibody interactions in blood serum.
Two categories of immune testing:
1. Direct testing:
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– Looking for presence of antigens.
2. Indirect testing:
– Look for antibodies that have formed against antigens.
 Test chosen based on the suspected diagnosis, cost, and speed with
which a result can be obtained.
IMMUNE TESTS:
 These tests are,
 Precipitation Tests:
 One of the easiest of serological tests.
 Antigens and antibody mixed in the proper proportion form large complexes called
precipitates.
A. Immunodiffusion:

10. INTRODUCTION TO IMMUNIZATION
 Determines optimal antibody and antigen concentrations.
B. Radial immunodiffusion:
 Used to measure specific antibodies in a person’s serum.
 Produces anti-antibodies.
 The human antibodies are the “antigen” in the test.
 Antibody is anti-human antibody.
 Agglutination Tests:
 Cross-linking of antibodies with particulate antigens causes agglutination.
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 Agglutination is the clumping of insoluble particles.
 Precipitation involves the aggregation of soluble molecules.
 Reactions are easy to see and interpret with the unaided eye.
 Hemagglutination:
– Agglutination of red blood cells can be used to determine blood type.

11. INTRODUCTION TO IMMUNIZATION
 Neutralization Tests:
A. Viral neutralization:
 Cytopathic effect.
 Viruses will kill appropriate cell cultures.
 Virus is first mixed with antibodies against it.
 Ability of virus to kill culture cells is neutralized.
 Absence of cytopathic effect indicates presence of antibodies.
 Identify whether individual has been exposed to a particular virus or viral strain.
B. Viral hemagglutination inhibition test:
 Useful for viruses that aren’t cytopathic
 Based on viral hemagglutination.
 Ability of viral surface proteins to clump red blood cells.
 Individual’s serum will stop viral hemagglutination if the serum contains
antibodies against the specific virus.
 Used to detect antibodies against influenza, measles and mumps.
 The Complement Fixation Test:
 Based on generation of membrane attack complexes during complement
activation.
 Detect presence of specific antibodies in an individual’s serum.
 Can detect antibody amounts too small to detect by agglutination.
 Labeled Antibody Test:
 Uses antibody molecules linked to some “label” that enables them to be easily
detected.
 Used to detect either antigens or antibodies.
A. Fluorescent antibody tests:
 Use fluorescent dyes as labels.
 Fluorescein is one dye used in these tests.
 Fluorescein-labeled antibodies used in two types of tests:
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– Direct fluorescent antibody tests.
– Indirect fluorescent antibody tests.
A. Indirect fluorescent antibody tests:

13. INTRODUCTION TO IMMUNIZATION
B. ELISA:
 Enzyme-linked immunosorbent assay.
 Uses an enzyme as the label.
 Reaction of enzyme with its substrate produces colored product.
 Commonly used to detect presence of antibodies in serum.
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14. INTRODUCTION TO IMMUNIZATION
 Antibody sandwich ELISA:
 Modification of the ELISA technique.
 Commonly used to detect antigen.
 Antigen being tested for is “sandwiched” between two antibody molecules.
 Advantages of the ELISA:
 Can detect either antibody or antigen.
 Can quantify amounts of antigen or antibody.
 Easy to perform and can test many samples quickly.
 Plates coated with antigen and gelatin can be stored for later testing.
C. Western blot test:
 Technique to detect antibodies against multiple antigens.
 Advantages over other tests.
 Can detect more types of antibodies.
 Less subject to misinterpretation.
RECENT DEVELOPMENTS:
 Immunofiltration:
 Rapid ELISA that uses antibodies bound to membrane filters rather than
polystyrene plates.
 Membrane filters have large surface area.
 Assay quicker to complete.
 Immunochromatography:
 Very rapid and easy-to-read ELISAs.
 Antigen solution flows through a porous strip and encounters labeled antibody.
 Visible line produced when antigen-antibody immune complexes encounter
antibody against them.
 Used for pregnancy testing and rapid identification of infectious agents.
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REFERENCES:
 Prescott L.M.; “Microbiology”, 5th edition, 2002, Mcgraw hill
publication, New York, 764-778.
 Jain N.K.; “Pharmaceutical microbiology”, 2nd edition, 2005, Vallabh
prakashan, pithampura, New Delhi, 168-184.
 www.mhhe.com
 www.ijrpc.com
 www.ijpbs.net
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