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Step 1
Use the tweezers to pull out a segment of DNA from
the hepatitis B virus.
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A subunit vaccine makes use of just a small portion
of a pathogen. For a virus, the vaccine can contain
just a piece of the protein coat that surrounds the
virus's DNA (or RNA). Even small portion of a virus
is sometimes enough to stimulate an immune response
in the body.
There are several ways to produce a vaccine for
hepatitis B vaccine. For your vaccine, you'll use
genetic engineering techniques.
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Step 2
Add the segment of DNA to the DNA of a yeast cell
(which is in the yeast culture).
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A segment of the virus's DNA is responsible for the
production of the virus's protein coat. You will add
this segment to the DNA within a yeast cell.
The yeast cell, as it grows, will "read" the viral
DNA incorporated in its own DNA and produce the
protein that makes up the protein coat of hepatitis
B.
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Step 3
Use the purifier to isolate the hepatitis B antigen
produced by the yeast cells.
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The vaccine, once administered, will stimulate the
immune system to attack the antigen (i.e., the
protein coat). Then, if the inoculated person is
later exposed to the virus, the immune system will
quickly respond to the invader and eliminate it
before it has a chance to spread widely.
To finish making the vaccine, you need to separate
the proteins from the yeast cells.
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Step 4
Fill the syringe with the purified hepatitis B
antigen.
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The isolated hepatitis B protein, produced by the
yeast cells, contains none of the viral DNA that
makes hepatitis B harmful. Therefore, there is no
possibility of it causing the disease.
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Done
The hepatitis B vaccine is complete.
Select another pathogen.
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Congratulations. You have produced a subunit vaccine
for hepatitis B.
Another example in the subunit category is the
anthrax vaccine approved in the U.S. (The countries
of the former Soviet Union have an attenuated
version of the vaccine.) The U.S. vaccine is
currently administered to military personnel.
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