EDIBLE VACCINATIONS

Vaccinating people with edible plants is a new idea that appears to hold great promise.

NSF and other government agencies are funding research that could make vaccinating large groups of people easier and smoother. NSF provides funds for the research that has developed much of the knowledge and many of the tools necessary to engineer plants in order to deliver vaccines in an edible form.

Current research is focused at mixing viral or bacterial DNA in a formula, which is then inserted into soil bacteria. When a plant takes on the bacteria, therapeutic DNA becomes stitched into the plant's genetic makeup.

As the plant grows, its cells start to produce whatever proteins the new genes are designed to make. When the plant or fruit is eaten, immunization starts, prompting the body to produce the appropriate antibodies.

Bananas for vaccines
Researchers in Ithaca, NY, are working to develop bananas to produce antigens so that they can be used as edible vaccines against diarrhea caused by the E. coli bacteria.

Recently, these researchers transformed potatoes to produce an E. coli protein that then produced immune responses in human volunteers who ate the raw potatoes. These researchers are now trying to introduce the same antigens in raw bananas, a medium more palatable than raw potatoes.

Future research
Edible vaccines hold great potential, especially in Third World countries where transportation costs, poor refrigeration and needle use complicate vaccine administration.

While research is also being conducted with laboratory animals, diabetics may someday benefit from an edible form of insulin. NSF and other government-agency and industry-funded researchers have developed technologies that permit the introduction of a hybrid gene that produces human insulin in potatoes.

For diabetics, insulin-bearing potatoes may help train the body's defenses to stop reacting to insulin as if it were a foreign material.