Edible Vaccines

In the past few years, agricultural biotechnology has progressed in leaps and bounds. It started with the commercial success of “Golden Rice”- a genetically modified crop, aimed to provide better “Vitamin-A” nutrition to those populations that suffer from Vitamin- A deficiency. After Golden Rice came the Indian invention- Bt. Cotton. This cotton crop could reduce the damage caused by Bollworm, by causing an adverse effect on the insects that feed on it. It therefore helped in increasing yield by decreasing the damage. The other commercial GM crops were namely, “Flavr Savr” Tomatoes, Bt. Brinjal and many more, each aiming at either increasing yield or reducing spoilage.

Biotechnologists in recent years have come up with a new concept, enhancing the idea behind “Golden Rice”. This new concept is about Food Vaccines. The difference here lies, that crops like “golden rice” provided extra nutrition that naturally didn’t occur in it. But food vaccines are GM crops that would provide extra added “immunity” from certain diseases.

Food Vaccines or Edible Vaccines have many potential advantages. These GM plants could be grown locally, and cheaply, using the standard growing methods of a given region. Homegrown vaccines would also avoid the logistical and economic problems posed by having to transport traditional preparations over long distances. And, being edible, the vaccines would require no syringes.

But with advancement, come many hurdles and problems. One of the key goals of the edible-vaccine pioneers is to reduce immunization costs. It is postulated that edible vaccines would be far cheaper than current injectable vaccines since they would not have to undergo the expensive purification and refrigeration of traditional vaccines, and transportation costs would be much reduced. Even if edible vaccines are cheaper, it is not assured that this will lead to increased vaccination coverage, since in many cases the cost of the vaccine is a small part of the whole package. According to the WHO, to immunize a child, the cost is no more than $1 for six big vaccines, but $14 is the cost for the total programme which includes- laboratories, transport, cold chain, personnel and research.
In special cases, for the newer, more expensive vaccines, such as hepatitis B and AIDS, the cost of the vaccine plays a more significant role, but the nature of the vehicle (apples or syringe) will still only represent a small part of the total cost.

Research into edible vaccines is still at a very early stage and scientists have a long way to go in proving their efficacy. Getting plants to express adequate amounts of the vaccine, is proving challenging enough, let alone translating that into an appropriate immunological response in people. Producing stable and reliable amounts of vaccines in plants is complicated by the fact that tomatoes and bananas don’t come in standard sizes! There may also be side-effects due to the interaction between the vaccine and the vehicle. People could ingest too much of the vaccine, which could be toxic, or too little, which could lead to disease outbreaks among populations believed to be immune.
Despite the un-surety of these vaccines, they can prove to be bliss for the underprivileged, if they are a success as they will be easily reachable to a wide population. Even “Golden Rice” faced a lot of problems till its final approval and now it has proved as a major success to the underprivileged population of Africa.

Shambhavi Sharan

[Image source:http://www.bio.davidson.edu/people/kabernd/seminar/2002/edible/Syringe.jpg]