Transcript - PEER - Texas A&M University

Partnership for Environmental Education and Rural Health
Texas A&M University
http://peer.tamu.edu
Vaccines control diseases
and can protect people
and animals from illness
and death.
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Infections
What vaccines are
How vaccines work
History of vaccination research
Future developments expected
Dog and cat vaccination
Microbes invade the body
Improve general health - proper
nutrition, exercise, healthy
lifestyle, etc.
Vaccinate
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Eating healthy food, taking
vitamins, and regular
exercise stimulates the
immune system.
Good sanitation practices
also limits an infectious
agent’s ability to spread to
you and others.
Check our Web site on Body Defenses
Vaccinations help both you and
your best friend stay safe.
Target
specific
diseases
Protect those
who are
vaccinated
Stop
epidemics
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Vaccinate the largest possible number of
individuals in the population at risk.
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Vaccinate each individual no more
frequently than necessary.
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Vaccinate only against infectious agents to
which individuals have a realistic risk of
exposure and subsequent development of
disease.
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Vaccines consist of killed or
weakened microbes that
stimulate the immune system
against that microbe.
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Why must the microbes be killed
or weakened?
Some infectious agents can
change their genetic makeup
making it difficult to produce a
vaccine.
Polio, Haemophilus Influenza B,
Diphtheria, Tetanus, Pertussis,
Hepatitis A, Chickenpox, Measles,
Mumps, Rubella, and Hepatitis B.
Have you
had yours?
Microbes grown on
suitable medium
Purified to remove compounds that
could cause allergic reactions
(not always possible)
1.
2.
3.
4.
5.
What are two main ways to improve resistance
to infection?
Why is vaccination important?
What should the goals of vaccination be?
What is a vaccine?
How are vaccines made?
Your Body’s Defense System
See separate lesson in this series on Immunity
Passive
Active
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Exposure to an
infectious agent triggers
production of antibodies
and may cause the
disease.
Vaccines trigger the
immune response
without causing the
disease (usually!)
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Person is injected with
antibodies
(immunoglobulins).
Immediate protection, but
can’t last long because it
does not stimulate the
immune system to make
it’s own antibodies.
Passive immunization
will never cause the
disease.
Weakened Vaccines
•
Produced by weakening a live virus or
removing it’s disease-causing ability.
Pros
Cons
- They elicit an immune system
- They have to be stored under special
conditions, like refrigeration.
response and the formation of
antibodies so you only have to
receive the vaccine once or
twice.
- They can mutate and might cause the
disease (very rare).
Inactivated Vaccines
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These vaccines are produced by killing the
infectious agent.
Pros
- They do not have to be
refrigerated.
- They will never come back
to life and cause the
disease.
Cons
- They usually require
booster shots because they
only weakly stimulate the
immune system to make
antibodies.
Toxoids
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Made by inactivating the toxin that
some infectious agents create.
Used against Tetanus and Diphtheria.
Pros
- You only have to have the
vaccine once or twice.
- They will never be
reactivated and cause the
disease.
Cons
- They have to be
refrigerated.
Subunit Vaccines
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Made by taking apart an infectious agent
and only using the antigenic part (the part
that stimulates an immune response).
Example vaccines: Hepatitis B and
Streptococcus pneumoniae
Pros
- They cannot cause the
disease.
Cons
- They are more difficult to
make and require new,
expensive technology.
1.
2.
3.
4.
How do vaccines work?
What are antibodies and what do they do?
What is the difference between active and
passive vaccination? What are the advantages
and disadvantages of each?
Research is often aimed at developing sub-unit
vaccines. Why?
1798 – smallpox
1955 - polio (inj.)
1885 – rabies
1962 - polio (oral)
1897 – plague
1964 - measles
1923 – diphtheria
1967 – mumps
1926 – pertussis
1969 – rubella
1927 – TB
1970 – anthrax
1927 – tetanus
1977 – pneumonia
1935 - yellow fever
1981 – hepatitis B
1945 - influenza
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In the late 1700s, a very deadly
virus called smallpox was
spreading through England.
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Milk maids did not get smallpox
(yet were continuously exposed
to cowpox).
In 1796, Edward Jenner inoculated a
boy with cowpox, then showed later that
smallpox inoculation did not infect him.
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Creation of an anthrax vaccine by
growing the microbe in a culture
medium until it lost ability to
cause sickness. Today’s vaccine:
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99% effective against cutaneous
anthrax
See PEER professor presentation on
anthrax
Creation of a rabies vaccine by
growing the microbe in duck
eggs until it lost ability to cause
sickness.
1.
2.
3.
What was Edward Jenner’s contribution to
vaccination research?
What were Louis Pasteur’s first contributions
to vaccination?
What was the average human life span before
the advent of vaccination? What is it today?
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Genetically engineer foods to contain parts of
disease-causing organisms.
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Such a vaccine could be “grown” around the
world, even in underdeveloped countries.
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Eliminates the need for expensive storage,
transportation, refrigeration
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Hoping to prevent another
1918 flu epidemic disaster.
Many viruses can change their
genetic makeup to become
stronger and resist vaccines or
antibiotics that were once
effective.
Gene sequencing of these
microbes helps scientists to:
Understand how microbes invade
and attack.
 Identify antigenic sites as targets
for drugs or sub-unit vaccines.
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One strategy for genetically engineered vaccines
Identify an antigen
Identify gene that
makes antigen
Insert gene into a
harmless virus
Infect patient
with the virus
Gene makes the
antigen inside
the patient
Antigen induces
antibody production
by the patient
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These rare reactions range from allergy
symptoms to sudden death. Pets should be
monitored for vaccine reactions soon after
vaccinations.
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Anaphylaxis is a rare, life-threatening,
immediate allergic reaction. Readily treated by
a veterinarian, but if untreated, it may result in
shock, respiratory and heart failure, or even
death.
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Pain, swelling, redness, and irritation can occur
at the injection site. Mild fever, decreased
appetite, and depression may also occur. If you
notice any of these signs in your pets, contact
your veterinarian immediately.
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These reactions may sound scary, but the risks
of not vaccinating dogs and cats are far greater.
Cindy Chang
Class of 2009
College of Veterinary Medicine
Texas A&M University
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Rabies – for all pets! (Killed Virus)
Dogs
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Cats
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Parvovirus – Modified Live Virus
Distemper – Modified Live Virus
Feline Leukemia Virus – Killed Virus
Panleukopenia - Modified Live Virus
Horses
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Tetanus - Toxoid
- Encephalomyelitis - Killed
West Nile Virus – Killed - Flu/Rhino - Killed
Strangles – Inactivated
1.
Young animals need vaccinating early and
often because their immune system is not yet
developed.
2.
Later, booster shots may be needed because
protection “wears off.”
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Pets need to be healthy to receive
vaccination. Sick animals do not
respond well to vaccination.
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Veterinarians provide health and
nutrition information that you can’t
get from pet supply stores.
Pets that visit the veterinarian once a
year are healthier, happier, and live
longer.
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Rabies vaccine is required by law in many
states. Why?
Puppies should receive a single dose of
killed rabies vaccine at 16 weeks of age.
Adult dogs with unknown vaccination
history should also receive a single dose of
rabies vaccine.
A booster is required one year later for both
puppies and adult dogs. Rabies vaccination
should be performed every 3 years.
See separate lesson on
rabies in this series.