CASE STUDY : Needle Of Hope
1. http://www.youtube.com/watch?v=uA5chESBghw&feature=related
2. http://www.youtube.com/watch?v=EPXMRZzaZtQ
3. http://www.youtube.com/watch?v=oBn385Mun6A
PURPOSE: To have a better understanding of how
viral infections spread and how vaccines and the
immune system work to protect us against viruses
and bacteria.
Part I – Small Pox
The initial symptoms of smallpox, 7 to 17 days after exposure,
include the acute onset of fever, chills, headache, nausea,
vomiting and severe muscle aches. During this time, the infected
person feels fine and is not contagious. The symptoms of
smallpox begin with high fever, head and body aches, and
sometimes vomiting. A rash follows that spreads and progresses
to raised bumps that crust, scab, and fall off after about three
weeks, leaving a pitted scar. This stage generally lasts for two to
four days and can be accompanied by flushing of the skin. By the
fourth day of illness, the fever drops and
the characteristic smallpox rash appears.
There are two types of smallpox: variola major and variola minor.
Variola major is the more severe form and has a 30-50% fatality
rate among those who are unvaccinated (3% in vaccinated
persons). Variola minor has a 1-2% fatality rate in unvaccinated
individuals.
A)The source of Cowpox was probably the cows
milked by the dairy maids as it was most
prominent on their hands.
B) The virus would probably infect anyone in
close contact with cows or those having
contact with people with Cowpox.
C) After the injection of smallpox, James Phipps
could have developed a very virulent infection
of smallpox which could have made him very
sick or it may have even killed him.
D)
It is too dangerous and unethical to test
things out on humans as the first test subjects.
Most pharmaceutical companies start testing
on small mammals like rodent (rats/mice)
then move onto test on primates.
E) Cowpox is far less virulent than Smallpox,
because the Smallpox virus reproduces at a
much faster rate and gets a bigger jump on the
immune system.
F) Cowpox antibodies are similar shape to the
Smallpox antibodies, therefore, they bind onto
the Smallpox antigens and stop the virus from
spreading while marking them for destruction.
** Ask to see a parent's left arm for scar.
PART II – Rabies Vaccine
Fever and lethargy in dogs can be seen as the first symptoms of
dog rabies. Usually, the dog wants to be left alone and it also
shows loss of appetite. The second stage manifests as the dog
becomes seemingly mad as seizures and irregular muscle
movement occur. The dog becomes restless as it also becomes
disoriented and does not recognize its owners.
In humans, it is usually picked up from a bite or even a lick
from a rabid animal. The virus multiplies in skeletal muscle and
connective tissues, but remains localized (hidden from the
immune system) for days to months (average 4-8 weeks). Then
it breaks out and infects nervous tissue. When it gets into the
nervous tissue, the immune system cannot access it. Human
experiences muscle spasms of the mouth and throat along with
severe nerve pain (neuralgia), especially when liquids are being
swallowed. Eventually, the virus causes extensive damage to
the brain and spinal cord. The individual, becomes delusional
and combative; death is almost always inevitable.
G)
Because the Rabies virus reproduces inside
host cells, the immune cells have a hard time
detecting it and only after it is detected can
the immune system take steps to constructing
the proper shaped antibodies that will wipe it
out.
H)
The symptoms of Rabies do not show up
until the virus has had adequate time to
reproduce inside the host cell.
I) Louis Pasteur wanted to weaken the virus so
that the immune system could get exposure to
it when injected with the vaccine. The
immune system could then get a jump on the
virus allowing the immune system to make
antibodies at a faster rate than the virus could
spread. When this occurs the majority of
symptoms of the disease will not show up.
J) http://www.youtube.com/watch?v=lrYlZJiuf18&feature=fvw
PART III – POLIO Vaccine
K ) The different “Strains” of Polio virus are
probably caused by slightly different mutations of
the Polio Virus. The virus capsids may have slightly
different shapes with slightly different antigens.
The antibodies for one polio virus may not be the
correct shape for the other polio strains.
CASE STUDY Q’s 2 & 3.
2. If a vaccine were taken orally the digestive
enzymes could possibly destroy the vaccine before
it could be properly absorbed into the
bloodstream.
3. Vaccines rely on the body’s immune system to
prevent disease. Chemical therapies (like
antibiotics) act by killing the microbe. Those
chemicals target some of the key enzymes that
those infectious agents use. The problem with
Viruses is that they use all the same enzymes that
your body cells use, so Antiviral medications are
very hard on the body.