Edible Vaccines
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Vaccine Production Economic
Dilemma
Vaccines
have been used for years to help inoculate the human population against a
variety of diseases. Gradually the
field has developed new vaccines to add to the list of diseases that we can
be inoculated against, but this development has resulted in increased costs
and supplies for the creation of these vaccines.
The use of animal cells or yeast coupled with facility requirements
for refrigeration and other factors is very costly (Langridge
2000). These production costs result
in expensive vaccines which have to be paid by the patient needing the vaccination.
Moreover, the creation of subunit vaccines leads to an increased demand
for proper refrigeration and storage for the newly discovered vaccines (Langridge
2000).
Global Problem
Not
only are these vaccines way too expensive for children in third-world
countries, but these countries do not have adequate health care systems for the
storage or administration of these vaccines.
Currently 20% of the world’s infants do not receive proper immunizations
which lead to 2,000,000 unnecessary deaths each year (Langridge
2000). The production of edible
vaccines creates the potential to use native foods in these third-world
countries to be used as vectors for the vaccines. This explains why bananas, rice, corn, wheat,
and soy lead the pack in edible vaccines.
Advantage of Edible Vaccines
Over Traditional Vaccination
The
cost of producing edible vaccines will be as much as 10 to 50 times lower
as compared to traditional vaccine production (Giddings,
G. et al 2000). Another more obvious
advantage is that syringes will not be required, which allows vaccinations
to be less painful and more importantly reduces the risk of transmission of
infectious diseases which run rampant through most third-world countries. Instead, the vaccines can be delivered by food
products like bananas which can be eaten raw and served in a puree form (Langridge
2000).
Subunit Preparation Vaccines
Traditional
vaccine production used a weakened form of the actual virus that a person
is being inoculated against to induce the person’s immune system to produce
the proper antibodies against this weakened strain and therefore creating
immunity. The only problem with this methodology is that
there is a slight risk that the organism will actually not be weakened enough
and will infect the vaccinated person. A
new advance in technology known as subunit preparations use the antigenic
proteins produced from a pathogen’s genetic material (Langridge
2000). The advantage of these subunit
preparations is that there is absolutely no way the proteins would be able
to reform into an infectious organism (Langridge
2000). Anytime you produce a “better”
method you typically encounter a greater cost, which is the case with these
subunit preparations.
Successful Animal Testing
Transmissible
Gastroenteritis Virus (TGEV) is a disease which affects pigs (Giddings,
G. et. al 2000). Scientists at
ProdiGene were able to insert the vaccine for this virus into the corn eaten
by the pigs, and they discovered that the pigs in fact were inoculated for
TGEV by the genetically altered corn (Giddings,
G. et. al 2000). This animal test
creates a powerful argument that edible vaccines do work and have a lot of
potential for future vaccination means.
Current Research
Currently,
a lot research has been focused on using edible vaccines to inoculate against
hepatitis B which affects the liver.
Charles Arntzen from
For
most of these vaccines or subunit vaccinations, bananas seem to be the desired
vector. The advantage of bananas is
that they can be eaten raw as compared to potatoes or rice that need to be
cooked [typically], and bananas can also be consumed in a puree form (Langridge
2000). Research is leaning towards
the use of bananas as the vector since most third-world countries, who would benefit most from edible vaccines, are in tropical
climates that are suitable for growing bananas.
Scientists have also discovered that fruits with high water content
could result in proteolysis (Giddings,
G. et. al 2000). Experimentation
with freeze-dried food to create pellets or powder is now being investigated
to help avoid proteolysis and overall efficacy (Bonetta
2002).
This webpage
was created by David Shelburne ’04 & Paul Toran ’03 as an assignment for an
undergraduate
course—Bio
361: Genetically Modified Organisms—at
© Copyright 2002 Department of Biology,