Dr.
Heribert Warzecha from Boyce Thompson Plant Research Institute is
working on a plant vaccine that can be put into tomatoes against
human papilloma virus (type 11 L 1) that causes genital warts.
Dr.
Hugh Mason and his team are conducting the first human trials of
potatoes engineered with an antigen for Hepatitis B virus that causes
fatal liver diseases. They are trying to adapt the potato plants
to the above antigen dose as potato is a more practical crop for
developing countries.
Dr.
Schuyler Korban, professor of plant genetics at the University of
Illinois, is trying to develop a palatable apple juice-based vaccine
against the highly contagious respiratory syncytial virus that kills
up to 5,000 children in the United States each year. So far, the
vaccine is being developed in tomato and potato plants.
The
success of the clinical trials on animals and humans have underlined
the possibilities of developing plant vaccines in tomatoes, potatoes
and bananas to combat allergies or to correct auto-immune diseases
along with the eradication of infectious diseases. In most developing
and underdeveloped countries, bananas provide more then a quarter
of all food calories and feed millions of people all over the globe.
United Nations Food and Agriculture Organisation (FAO) ranks banana
as the world’s fourth most important food crop. Banana is considered
a perfect tool for an oral vaccine as it is cheap, abundant and
can be eaten raw, which prevents destruction of heat labile vaccines.
The equipment and cost requirements for banana production are less
than the techniques employed in production of animal-cell vaccines.
The approximate cost for a banana containing vaccine is 2 cents
a dose against the current $ 125 per dose for animal vaccine.
Issues
and concerns
Although
the technology sounds promising on paper and holds true for certain
research findings, it also raises certain issues, such as:
Will
plants engineered to carry antigen genes produce functional copies
of the specific proteins?
When
fed to test animals, will the antigens be degraded in the stomach
before having a chance to act?
If
the antigens do survive, will they attract the attention of the
immune system?
Will
the response be strong enough to defend the animal against infection?
Will
this response protect an individual against future attacks of the
pathogen?
The
promoters of EVP must also ensure that the growth and processing
of plant vaccines should never enter the food supply. These precautions
would include greenhouse segregation of medicinal crops from food
crops to prevent out-crossing, and separate storage and processing
facilities.
Opportunities
for India
Agriculture
is an integral part of the Indian economy. India surpasses many
other countries in terms of available agricultural land, skilled
workers, infrastructure facilities and updated technological know-how.
India is one of the leading producers of banana in the world. Over
the years, the horticulture sector has shown a manifold increase
in the production and export of fruits and vegetables.
Considering
the current global scenario of biotechnological revolution and agribusiness
opportunities, India can play a major role in plant-based vaccine
production. The biotech-pharma industry, along with progressive
farmers, can not only promote EPV, but can emerge as leaders in
the international market. It can lead to an export-oriented agri-business
activity that will bring self-sufficiency for farmers and smaller
agri-business ventures in the country.
The
authors are VP, SkillNet Solutions Inc., USA. Lecturer, K C College,
Mumbai
The author is a consulting biotechnologist
