Sr TABLE OF CONTENTS Pg No.
No.
1. Introduction
2. History of vaccination and its
invention
3. Principal of vaccination
4. Difference between vaccination and
immunization
5. Examples of vaccination
6. Types of vaccines
7. Stages of vaccine development
8. Contents of vaccines
9. Importance of vaccines in COVID
10. Mission Indra Dhanush
11. Future scope of vaccine
development
12. Difference between mRNA vaccines
and the traditional vaccines
13. Conclusion
INTRODUCTION
Vaccination is a crucial medical intervention that helps
protect individuals from various infectious diseases. It
involves the administration of a vaccine which contains
weakened or inactive forms of specific pathogens or
their components. When a person receives a vaccine,
their immune system is stimulated to produce an
immune response, including the production of
antibodies. This response helps the body recognize and
fight off the actual disease-causing pathogens if they
are encountered in the future. Vaccination has been
instrumental in preventing the spread of diseases such
as polio, measles, and influenza, saving countless lives
worldwide. It is a safe and effective way to build
immunity and is recommended for people of all ages to
maintain personal health and contribute to public
health efforts.
HISTORY OF VACCINATION and its
INVENTION:
The history of vaccines dates to ancient times when
people observed that individuals who survived certain
diseases were immune to future infections. However,
the formal development of vaccines began in the late
18th century. Edward Jenner, an English physician, is
often credited with inventing the first vaccine. In 1796,
he successfully used cowpox material to protect against
smallpox, a deadly disease at the time.
Jenner observed that milkmaids who had contracted
cowpox, a relatively mild disease, did not get infected
with smallpox, a highly contagious and deadly disease.
This led him to hypothesize that cowpox could be used
to protect against smallpox.
In 1796, Jenner conducted an experiment in which he
took material from a cowpox blister on a milkmaid's
hand and used it to inoculate an 8-year-old boy named
James Phipps. The boy developed a mild fever and a
few blisters, but he recovered within a few days. Later,
Jenner exposed the boy to smallpox, but he did not get
sick. This experiment demonstrated that cowpox could
protect against smallpox and laid the foundation for
the development of vaccines.
Jenner's work laid the foundation for the concept of
vaccination, which comes from the Latin word "Vacca"
meaning cow. The term was coined because Jenner
used cowpox to protect against smallpox.
His discovery sparked interest and further research
into developing vaccines for other diseases. Over the
years, scientists and researchers made significant
advancements in vaccine development. Louis Pasteur, a
French chemist, is considered the father of modern
vaccines. In the late 19th century, he developed
vaccines for anthrax and rabies, which were major
breakthroughs in preventing these deadly diseases.
Since then, vaccines have been developed for
numerous diseases, including polio, measles, mumps,
rubella, hepatitis, influenza, and many others.
The invention of vaccines has revolutionized public
health by preventing the spread of infectious diseases
and saving countless lives.
Today, vaccines undergo rigorous testing and
evaluation to ensure their safety and efficacy. They are
produced using various methods, including inactivation
or weakening of the pathogen, using specific
components of the pathogen, or using genetically
engineered techniques.
The history and invention of vaccines have had a
profound impact on global health, leading to the
eradication or near-elimination of several
diseases. Vaccination remains a critical tool in
preventing the spread of infectious diseases and
protecting individuals and communities worldwide.
PRINCIPLE OF VACCINATION
The principal of a vaccine is to stimulate an immune
response in the body against a specific pathogen (such
as a virus or bacteria) without causing disease. This is
achieved by introducing a small, harmless piece of the
pathogen, or a weakened or dead version of the
pathogen, into the body. This is called an antigen.
When the immune system encounters the antigen, it
recognizes it as foreign and begins to mount a
response against it. Specialized cells in the immune
system, such as B cells and T cells, produce proteins
called antibodies that specifically target the antigen.
These antibodies can then recognize and neutralize the
actual pathogen if the person is later exposed to it,
preventing infection or reducing the severity of the
disease. It involves the function of T cells, which
present the antigen (becoming the antigen presenting
cells) and involving the formation of major
histocompatibility complex.
Vaccines have been very effective in preventing or
controlling a wide range of diseases, including
smallpox, polio, measles, mumps, rubella, hepatitis B,
and many others. They have also been instrumental in
reducing the spread of diseases and protecting
vulnerable populations, such as children, the elderly,
and people with weakened immune systems.
Phagocyte activities
Antigen-presenting cell (here dendritic cell) presenting
an antigen to a T cell
DIFFERENCE BETWEEN VACCINATION AND
IMMUNIZATION
VACCINATION IMMUNIZATION
Refers to the process of Refers to the overall
administering a vaccine, process of becoming
which contains weakened immune to a specific
or inactive forms of disease.
specific pathogens or
their components.
Involves the introduction Involves the development
of a vaccine into the body of immunity against a
to stimulate an immune specific disease, either
response. through vaccination or
natural exposure to the
pathogen.
Specifically focuses on the Encompasses the broader
act of receiving a vaccine concept of achieving
to prevent a particular immunity against various
disease. diseases.
Can be a single dose or Can be achieved through
require multiple doses, vaccination, natural
depending on the vaccine infection, or passive
and disease. immunization (receiving
pre-formed antibodies).
Aims to prevent the Aims to protect
occurrence of a specific individuals from a specific
disease by stimulating the disease by developing
immune system to immunity against it.
produce an immune
response.
Can be administered Can be achieved through
through various routes, various means, including
such as injection, oral, or vaccination, previous
nasal. infection, or maternal
antibodies passed from
mother to child.
Is a subset of Is a broader term that
immunization, as it encompasses various
specifically refers to the methods of acquiring
act of receiving a vaccine. immunity.
Examples include vaccines Examples include both
for diseases like polio, vaccines and natural
measles, and influenza. exposure to diseases,
leading to the
development of
immunity.
So, we can conclude that vaccination is a key
component of immunization, immunization can also
occur through natural exposure to a disease.
EXAMPLES OF VACCINATION
1. Measles vaccination: The measles vaccine is given to
protect against the highly contagious measles virus. It
is usually administered in two doses, with the first
dose given at 12-15 months of age and the second
dose at 4-6 years of age.
2. Influenza vaccination: The influenza vaccine,
commonly known as the flu shot, is given annually to
protect against the seasonal flu. It is recommended
for everyone above the age of 6 months, especially
those at high risk of complications from the flu, such
as the elderly and individuals with chronic health
conditions.
3. Polio vaccination: The polio vaccine is given to
protect against the poliovirus, which can cause
paralysis. It is usually administered in multiple doses,
with the first dose given at 2 months of age, followed
by additional doses at 4 months, 6-18 months, and 4-
6 years of age.
4. Hepatitis B vaccination: The hepatitis B vaccine is
given to protect against the hepatitis B virus, which
can cause liver disease. It is usually administered in a
series of three doses, with the first dose given at
birth, followed by additional doses at 1-2 months and
6-18 months of age.
5. HPV vaccination: The HPV vaccine is given to protect
against certain strains of the human papillomavirus,
which can cause cervical, anal, and other types of
cancer. It is recommended for both males and
females, usually starting at 11-12 years of age, and
administered in a series of two or three doses
depending on the age at which it is initiated.
6. Tetanus vaccination: The tetanus vaccine is given to
protect against the bacteria that cause tetanus, a
serious infection that affects the nervous system. It is
usually administered in a series of five doses, with
booster shots recommended every 10 years
throughout adulthood.
7. Meningococcal vaccination: The meningococcal
vaccine is given to protect against meningococcal
disease, which can cause meningitis and bloodstream
infections. It is recommended for adolescents and
young adults, with different types of vaccines
available for different age groups.
These are just a few examples of the many vaccines
available to protect against various diseases. Vaccination
is an essential tool in preventing the spread of infectious
diseases and maintaining public health.
TYPES OF VACCINES
There are several types of vaccines used to prevent
infectious diseases. Here are some of the most
common types:
1.Inactivated or killed vaccines: These vaccines contain
viruses or bacteria that have been killed or inactivated
through chemical or heat treatment. These vaccines
are often less effective than live vaccines, but they are
safer for people with weakened immune systems.
2.Live attenuated vaccines: These vaccines contain
weakened, or attenuated, forms of the virus or bacteria
that cause the disease. They mimic a natural infection,
resulting in a strong and long-lasting immune response.
Examples of live attenuated vaccines include the
measles, mumps, and rubella (MMR) vaccine and the
yellow fever vaccine.
3.Subunit, recombinant, or conjugate vaccines: These
vaccines contain only specific parts of the virus or
bacteria, such as protein or sugar molecules. They are
often safer than live vaccines and can be more effective
than inactivated vaccines. Examples include the human
papillomavirus (HPV) vaccine and the Hemophilus
influenzae type b (Hib) vaccine.
4.mRNA vaccines: mRNA vaccines use a small piece of
genetic material called messenger RNA (mRNA) to
instruct cells in the body to make a protein found on
the surface of the virus. This protein triggers an
immune response, which provides protection against
the virus. The Pfizer-BioNTech and Moderna COVID-19
vaccines are examples of mRNA vaccines.
5.Vector vaccines: Vector vaccines use a harmless virus
or bacteria to deliver a piece of genetic material from
the virus or bacteria that causes the disease. This
triggers an immune response that protects against the
disease. The Johnson & Johnson COVID-19 vaccine is an
example of a vector vaccine.
Each type of vaccine has its own advantages and
limitations, and the choice of vaccine used depends on
the specific disease being targeted and other factors,
such as safety and efficacy.
STAGES OF VACCINE DEVELOPMENT
Vaccine development is a complex process that
involves many stages, from basic research to clinical
trials and regulatory approval. Here are the general
steps involved in developing a vaccine:
1. Research and development: Scientists conduct
research to identify the pathogen that causes the
disease, study its structure and behaviour, and identify
potential vaccine targets.
2. Preclinical testing: In the preclinical stage, the
vaccine is tested in the laboratory and in animals to
evaluate its safety and efficacy.
3. Clinical trials: In the clinical trial stage, the vaccine is
tested in humans to determine its safety, efficacy,
and optimal dosage. Clinical trials typically involve
three phases: ·
Phase 1: A small group of healthy volunteers
receives the vaccine to evaluate its safety and
dosage.
Phase 2: A larger group of people receives the
vaccine to evaluate its safety and efficacy.
Phase 3: A large group of people receives the
vaccine to confirm its safety and efficacy and
compare it with other treatments.
4. Regulatory approval: Before a vaccine can be
approved for use, it must be reviewed by regulatory
agencies such as the FDA or the European Medicines
Agency. These agencies evaluate the data from clinical
trials and determine whether the vaccine is safe and
effective.
5. Manufacturing and distribution: Once the vaccine is
approved, it can be manufactured and distributed to
the public.
Developing a vaccine can take many years and requires
collaboration between scientists, regulatory agencies,
and pharmaceutical companies. However, vaccines
have the potential to save millions of lives and prevent
the spread of infectious diseases, so the effort is well
worth it.
CONTENTS OF VACCINE
Vaccines contain tiny fragments of the disease-causing
organism or the blueprints for making the tiny
fragments. They also contain other ingredients to keep
the vaccine safe and effective. These latter ingredients
are included in most vaccines and have been used for
decades in billions of doses of vaccine.
Each vaccine component serves a specific purpose, and
each ingredient is tested in the manufacturing process.
All ingredients are tested for safety.
Antigen
All vaccines contain an active component (the antigen)
which generates an immune response, or the blueprint
for making the active component. The antigen may be
a small part of the disease-causing organism, like a
protein or sugar, or it may be the whole organism in a
weakened or inactive form.
Preservatives
Preservatives prevent the vaccine from becoming
contaminated once the vial has been opened, if it will
be used for vaccinating more than one person. Some
vaccines don’t have preservatives because they are
stored in one-dose vials and are discarded after the
single dose is administered. The most commonly used
preservative is 2-phenoxyethanol. It has been used for
many years in a number of vaccines, is used in a range
of baby care products and is safe for use in vaccines, as
it has little toxicity in humans.
Stabilizers
Stabilizers prevent chemical reactions from occurring
within the vaccine and keep the vaccine components
from sticking to the vaccine vial.
Stabilizers can be sugars (lactose, sucrose), amino acids
(glycine), gelatin, and proteins (recombinant human
albumin, derived from yeast).
Surfactants
Surfactants keep all the ingredients in the vaccine
blended. They prevent settling and clumping of
elements that are in the liquid form of the vaccine.
They are also often used in foods like ice cream.
Residuals
Residuals are tiny amounts of various substances used
during manufacturing or production of vaccines that
are not active ingredients in the completed vaccine.
Substances will vary depending on the manufacturing
process used and may include egg proteins, yeast or
antibiotics. Residual traces of these substances which
may be present in a vaccine are in such small quantities
that they need to be measured as parts per million or
parts per billion.
Diluent
A diluent is a liquid used to dilute a vaccine to the
correct concentration immediately prior to use. The
most used diluent is sterile water.
Adjuvant
Some vaccines also contain adjuvants. An adjuvant
improves the immune response to the vaccine,
sometimes by keeping the vaccine at the injection site
for a little longer or by stimulating local immune cells.
The adjuvant may be a tiny amount of aluminium salts
(like aluminium phosphate, aluminium hydroxide, or
potassium aluminium sulphate). Aluminium has been
shown not to cause any long-term health problems,
and humans ingest aluminium regularly through eating
and drinking.
COVID-19 vaccination is of critical importance in the
fight against the pandemic. Here are some key reasons
why:
1.Protection against severe illness and death: COVID-
19 vaccines have been shown to be highly effective in
preventing severe illness, hospitalization, and death
from COVID-19. Getting vaccinated greatly reduces the
risk of experiencing severe symptoms if you do contract
the virus.
2.Community protection: Vaccination not only protects
the individual who receives the vaccine but also helps
to protect the entire community by reducing the
spread of the virus. This is especially important for
those who are unable to get vaccinated due to medical
reasons or age.
3.Ending the pandemic: Widespread vaccination is a
critical step in ending the pandemic and returning to a
sense of normalcy. The more people who are
vaccinated, the faster we can achieve herd immunity
and reduce the overall spread of the virus.
4.Protection against variants: Vaccines have been
shown to be effective against the current variants of
the virus, and getting vaccinated can help to prevent
the emergence of new variants that may be more
dangerous or resistant to current treatments.
5.Economic and social benefits: The pandemic has had
a significant impact on the global economy and social
well-being. Widespread vaccination can help to reduce
the economic and social impacts of the pandemic by
enabling society to return to normal activities such as
work, school, travel, and socializing.
In summary, COVID-19 vaccination is essential in
protecting individuals and communities from severe
illness, reducing the spread of the virus, and ultimately
ending the pandemic.
MISSION INDRADhanush
Mission Indradhanush is an ambitious immunization
program launched by the Government of India in 2014.
The mission aims to ensure full immunization coverage
for all children in the country, particularly those who
are unvaccinated or partially vaccinated. The name
"Indradhanush" symbolizes the seven colours of the
rainbow, representing the seven vaccines that are
targeted under this initiative. The program focuses on
reaching remote and underserved areas, as well as
urban slums, to provide life-saving vaccines against
diseases such as polio, measles, diphtheria, pertussis,
tetanus, tuberculosis, and hepatitis B. Through strategic
planning, intensive monitoring, and community
engagement, Mission Indradhanush strives to reduce
child mortality and morbidity rates by increasing
immunization coverage and protecting children from
preventable diseases.
FUTURE SCOPE OF VACCINATIONS
The future of vaccination looks promising with
continued advancements in vaccine development and
delivery. Here are some potential developments in the
field of vaccination:
1. mRNA vaccines: The success of mRNA vaccines in
preventing COVID-19 has led to increased interest in
using this technology to develop vaccines for other
infectious diseases, such as influenza, Zika, and HIV.
2.Universal flu vaccine: Researchers are working on
developing a universal flu vaccine that would protect
against all strains of the flu virus, eliminating the need
for annual flu shots.
3. Combination vaccines: Vaccines that protect against
multiple diseases are becoming more common, such as
the MMR vaccine that protects against measles,
mumps, and rubella. In the future, combination
vaccines may become even more widespread, making
it easier for people to get protection against multiple
diseases with fewer shots.
4.Needle-free vaccination: New delivery methods,
such as microneedle patches and nasal sprays, may
make vaccination more convenient and less painful.
5. Personalized vaccines: Advances in genomics and
personalized medicine may lead to the development of
vaccines that are tailored to an individual's genetic
makeup, providing more effective protection against
infectious diseases.
Overall, the future of vaccination looks promising, with
continued research and development leading to new
and improved vaccines that provide better protection
against infectious diseases. Vaccination remains one of
the most effective ways to prevent the spread of
infectious diseases and protect public health.
mRNA VACCINES DIFFER FORM TRADITIONAL vaccines:
1.Mechanism of action: Traditional vaccines work by
introducing a weakened or inactivated form of the virus
or bacteria into the body, while mRNA vaccines work by
introducing a piece of genetic material called
messenger RNA (mRNA) into the body. The mRNA
instructs cells in the body to produce a protein found
on the surface of the virus, which triggers an immune
response.
2.Speed of development: mRNA vaccines can be
developed more quickly than traditional vaccines
because they do not require the production of large
quantities of the virus or bacteria. Instead, the genetic
sequence of the virus can be quickly identified, and the
mRNA can be synthesized in a laboratory.
3.Safety: Because mRNA vaccines do not contain live
virus or bacteria, they are considered safer than
traditional vaccines. There is no risk of getting the
disease from the vaccine, and there is no risk of the
vaccine causing the disease to become more severe.
4.Storage and distribution: mRNA vaccines require
special storage and handling because the mRNA is
fragile and can degrade easily. They need to be stored
at very low temperatures until they are ready to be
administered.
5.Efficacy: mRNA vaccines have shown high efficacy
rates in clinical trials, including for the Pfizer-BioNTech
and Moderna COVID-19 vaccines, which have
demonstrated over 90% efficacy in preventing COVID-
19.
Overall, mRNA vaccines represent a new approach to
vaccine development that offers several advantages
over traditional vaccines, including speed of
development, safety, and high efficacy rates.
CONCLUSION:
In conclusion, vaccines play a crucial role in
safeguarding public health by preventing the spread of
infectious diseases. They have proven to be one of the
most effective and cost-efficient ways to protect
individuals and communities from potentially life-
threatening illnesses. Vaccines not only save lives but
also contribute to the overall well-being of society by
reducing the burden on healthcare systems and
preventing long-term complications. By ensuring high
vaccination coverage, we can create a safer and
healthier future for generations to come. It is essential
to prioritize vaccination efforts, promote vaccine
education, and maintain trust in the scientific
advancements that have made vaccines a cornerstone
of disease prevention.
