Edible Vaccines - No More Shots

Can You imagination, going to the doctor but instead of giving you a shot he hands you a banana? Researchers report that a vaccine built into an ordinary potato can trigger an immune response against a virus that causes food poisoning. The study has encouraged scientists hoping to produce vaccines in edible form for a host of infectious diseases

Currently, there are no good vaccines for the world's most devastating diseases, such as AIDS, malaria, and tuberculosis. But if they should become available, immunizing entire populations is often difficult. Vaccine injections are expensive; they require syringes, needles, and usually refrigeration; and they must be delivered by trained health care professionals. That's why researchers are engineering plants to produce key parts of viruses and bacteria, in the hope that the human body will take them for invaders and start producing antibodies against the organisms. But until now, no one has produced an edible vaccine that prompts such a response in humans.

A team, led by Charles Arntzen, president of the Boyce Thompson Institute for Plant Research in Ithaca, New York, engineered potatoes to produce a protein that makes up the structural shell of the Norwalk virus, a common cause of gastroenteritis. After being fed the modified potatoes, all but one of the 20 healthy adult volunteers had an increase in the number of antibody-secreting cells, and six of them had started secreting into the digestive system more antibodies that recognize the Norwalk virus structure.

The vaccine clearly triggered the immune system, says Arntzen, "but we need more vaccine per potato" to protect against an infection. And potatoes, while a convenient starting point, are not the vehicles of choice for future vaccines; they have to be eaten raw, which causes indigestion. Currently, most researchers are betting on bananas, which are easily grown in many developing countries, are commonly eaten raw, and can be fed to young children when immunization is most desired.

For now, all such clinical trials will involve modified potatoes or tomatoes. Both products can be easily freeze-dried, transported, and reconstituted. Since many target countries have a long history of herbal medicine, Arntzen is interested in working within already-existing ideas. "Our goal is not to make the decision for how we want (the freeze-dried dose) introduced," he said. "We want to work with them."

As of now commercial companies are only working on vaccines for animals. Because of the GMO controversy they are not interested in investing money for human vaccines.