Unit 1.4
Vaccinations
Unit 1.4 - Overview
Lesson 1.4 Vaccination - Overview
Preface
In this unit, you have studied diagnostic tests used to identify disease agents and
have examined how antibiotics can be used to treat bacterial infections.
In Lesson 1.4, you will discuss infectious disease prevention, specifically through
vaccination.
In the aftermath of the bacterial meningitis cases at Sue’s school, all student
medical records are reviewed and any student who did not receive the meningitis
vaccine is called back in for immediate immunization. Vaccination is a valuable first
line of defense against this debilitating infection and could make the difference
between a few isolated cases and a full-blown outbreak.
Unit 1.4 - Overview
In the first activity of the lesson, you will study the history of vaccination through
the eyes of scientist Edward Jenner. Smallpox, a highly infectious disease
characterized by small lesions on the skin, ravaged society for centuries.
Edward Jenner
• English physician/scientist who pioneered smallpox vaccine - the world's first
vaccine
• In 1796 - Jenner inoculated James Phipps, an 8 year old boy
• He scraped pus from cowpox blisters on the hands of a milkmaid who had
contracted cowpox and injected in both arms of Phipps
• Phipps presented with a fever and some uneasiness, but no full-blown infection
• Testing showed he developed an immunity to smallpox
Unit 1.4 - Overview
Vaccines trigger the production of antibodies against a particular pathogen; these
antibodies circulate to protect the body when and if it encounters the true invader.
You will:
1) complete an Internet interactive and view a presentation to explore the
techniques scientists use to produce vaccines
2) delve deeper into the science of molecular biology and learn how genetic
engineering can be used to manufacture viable vaccines
3) scan simulated plasmid and viral DNA and choose an appropriate restriction
enzyme to engineer a paper plasmid to produce a viral protein that can be
used as a vaccine
4) explore the career field of epidemiology
Unit 1.4 - Overview
Understandings
Vaccines are medical interventions that activate the immune system to recognize a
disease antigen and produce antibodies necessary to defend the body.
Vaccines can be produced in the laboratory by various methods, including
recombinant DNA techniques.
Epidemiologists are dedicated medical professionals at the heart of the public
health field who monitor the health of human populations, search for patterns in
the development of both infectious and chronic illnesses, assist in outbreak
investigations, and design disease treatment and prevention strategies.
Unit 1.4 - Overview
Knowledge and Skills
It is expected that you will understand:
1) How vaccines interact with the human immune system.
2) Many diseases have been eradicated by large-scale vaccination campaigns.
3) Various laboratory methods that are used to manufacture vaccines.
4) Plasmids can be employed as an important tool in genetic engineering and can
serve as vectors, vehicles for the movement of genetic information.
5) How molecular tools such as ligase and restriction enzymes are used to cut and
paste DNA from different sources.
6) How recombinant DNA technology can be used to produce vaccines.
7) Appropriate steps in an outbreak investigation.
8) The role of an epidemiologist to analyze disease data, design an epidemiologic
study, and evaluate prevention and therapy for chronic and infectious diseases.
Unit 1.4 - Overview
Essential Questions
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What is vaccination?
How does a vaccine activate the body’s immune system?
How has vaccination impacted disease trends in our country?
What methods are used to produce vaccines in the laboratory?
What is recombinant DNA technology?
What are the molecular tools used to assemble recombinant DNA?
How can recombinant DNA and bacterial cells be used to produce vaccines?
How can engineered plasmids be inserted into bacterial cells?
What is epidemiology?
How can epidemiologists assist with the detection, prevention, and treatment
of both chronic and infectious disease?
Unit 1.4 – Key Terms
Case-control study
Cohort study
DNA ligase
Epidemic
Epidemiology
Herd immunity
Inoculation
Plasmid
Recombinant DNA
Restriction enzyme
Vaccination
Vaccine
What is a vaccination and how
does it work?
The body is presented a dead or weakened form of the pathogen
to expose the immune system to the antigen.
This allows the B-cell to produce antibodies and memory cells.
Therefore, when the body is exposed to the antigen again the
immune system will be able to fight off the infection.
How has vaccination impacted
disease trends in our country?
Herd Immunity
• More individuals that are immune
decreases the incidence of the
disease and the occurrence of the
pathogen.
• With greater numbers immunized, it
is less likely that an unimmunized
person will encounter the pathogen.
• Mass vaccination confers indirect
protection for those who do not
receive the vaccine resulting in “herd
immunity”.
Effective Vaccines
• Have low levels of side effects or toxicity.
• Protect against exposure to natural, or wild forms of the
pathogen.
• Should stimulate both an antibody (B-cell) response and
a cell mediated (T-cell) response.
• Have long term, lasting effects that produce
immunological memory.
• Should not require numerous doses or boosters
• Are inexpensive, have a long shelf life and are easy to
administer.
Routes of Administration
• The majority of vaccines are
administered by injection
– Subcutaneous
– Intramuscular
– Intradermal
• Oral vaccines are available
for only a few diseases
Methods Used to Produce
Vaccines in the Laboratory?
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Killed
Attenuated
Toxoid
Subunit – recombinant DNA technology
Naked DNA
Similar Pathogen
2 goals for every vaccine
– Contains Antigen so we can produce antibodies
– Pathogen will not be harmful
Types of Vaccines
Killed whole cells or inactivated viruses
– Pathogen is killed due to heat or radiation and inserted into
the body.
– Even though they are harmless, they still contain
recognizable antigens on their surface
– Because the microbe does not multiply, larger doses and
more boosters are required.
Types of Vaccines
Live, attenuated (weakened) cells or viruses
– Pathogen is grown under non ideal conditions for several
generations, causing the pathogen to evolve.
– Due to natural selection the pathogen is now adapted to the
new environment.
– When placed in humans they still have the antigens, but will
be weak in the body’s environment so they will not harm.
– Longer-lasting and require fewer boosters
– Disease agent could mutate back to pathogenic strain
Types of Vaccines
Toxoid vaccines
– Grow pathogen and collect the toxins produced by the
antigen .
– Purified toxin injected into the person with another vaccine
and the body will elicit immune response.
Genetically engineered – Recombinant DNA Tech
– Genes for microbial antigens are inserted into a plasmid
vector and are cloned in appropriate hosts.
– The resultant protein product is used to provoke immune
system.
DNA vaccines – Naked DNA
– These vaccines contain all or part of the pathogen DNA,
which is used to “infect” a recipient’s cells.
Subunit
Vaccine
Gene for antigen from
pathogen is put onto a
plasmid and inserted into
another organism. This
organism can produce the
antigen, which is used to
produce the vaccine.
What is recombinant DNA
technology?
joining together of DNA molecules (from two different
species) that are inserted into a host organism to produce
new genetic combinations that are of value to science,
medicine, agriculture, and industry.
What are the molecular tools used
to assemble recombinant DNA?
• Restriction Enzymes cut DNA and open Plasmid
• Ligase connect DNA fragment to plasmid at the sticky ends
• This forms a recombinant plasmid that has a specific gene in it.
recombinant
DNA
technology
Inserting engineered
plasmids into bacterial
cells
• The recombinant plasmid is
made and inserted into the
bacteria via transformation.
• The bacteria can express the
gene that was placed into
the plasmid to produce the
necessary antigen for the
vaccine.
Similar Pathogen
Vaccine
Insert a similar pathogen to what you want to
vaccinate against. This pathogen is not as harmful to
humans as the pathogen you are vaccinating against.
It contains a similar enough antigen that we can
develop antibodies to kill the pathogen.
Naked DNA
Vaccine
Gene for antigen from
pathogen is put onto a plasmid
and inserted into a bacteria to
replicate the plasmid.
The plasmid is purified and
placed into the body.
The body cells can uptake the
DNA and begin making the
antigen.
What is epidemiology?
Epidemiology is the study of the spread, cause, and effects of
diseases in certain populations.
How can epidemiologists assist with
the detection, prevention, and
treatment of both chronic and
infectious disease?
• They analyze data, conduct surveys, and perform tests, to
identify the cause and spread of the disease.
• They develop informative tools and use preventative
measures to stop the spread of the disease.