From left, research team members Nicole Higgs, Hugh Mason and Charles Arntzen, president of Boyce Thompson Institute, and Rodolfo Lopez-Gomez, a visiting scientist from Mexico, pose among banana plants used in developing edible vaccine. Adriana Rovers/University Photography
Researchers at the Boyce Thompson Institute for Plant Research Inc. at Cornell now will begin exchanging new vaccine information with scientists in developing countries, starting with Mexico, thanks to a new Rockefeller Foundation grant.
"This is very good news. For the oral vaccines we're researching here, this clears the way for international technology transfer," said Charles J. Arntzen, president of Boyce Thompson Institute (BTI). "This grant is an endorsement, and it has become a first step in the process of bringing our research to people who can use it."
Traditional vaccines that inoculate children against enteric diseases like diarrhea and cholera are very expensive to send to developing countries. Arntzen and BTI researchers are developing genetically changed foods that are grown with the vaccine already in them, as a cheap and easy way to deliver vaccines to children throughout the world. For example, the BTI researchers have sought to genetically install the vaccine into bananas.
Specifically, the Rockefeller Foundation grant $58,000 for three years will allow Miguel Gomez-Lim of the Centro de Investigacion y de Estudios Avanzados del I.P.N. (CINESTAV), Mexico City, a government health agency, to collaborate with BTI researchers.
Gomez-Lim and his American colleagues will try to verify the value of "edible" vaccines and to begin educational efforts in Mexico to facilitate the rapid adoption of these vaccines for safe and effective use.
"The goal is to deliver a 'technology package' which makes the eradication of one or more infectious diseases possible on a global scale," Arntzen said. While work progresses on the vaccines for enteric diseases, Arntzen hopes that this research eventually will lead to an edible HIV vaccine that can be used cost-effectively around the world as an inoculation against AIDS.
Earlier this year, BTI researchers showed that edible vaccines work in animal tests, by feeding animals raw potatoes that had been modified to include the vaccine agent. Human clinical trials already have begun with raw potatoes.
Enteric, or diarrheal, diseases kill more children in developing countries than any other diseases. For children under age 5 in developing countries, one-third of deaths are from these types of illnesses. Almost 25 percent of children who die between the ages of 5 and 14 lose their lives to enteric illnesses. These diseases account for between 3 million and 5 million children's deaths annually, and many could be prevented if such vaccines were available.
"If less expensive vaccines were available, they would have an immediate impact around the world," Arntzen said. "A crop can be made to produce 'edible vaccines,' and these vaccines will elicit an immune response when the food is eaten." When mice were given the edible vaccine, Arntzen explained, they produced antibodies that inactivated diarrhea-causing bacterial toxins.
Cost is a major factor: traditional vaccines today cost between $50 and $100 apiece, while this new mechanism the banana costs only pennies to deliver.
Eight banana plants grow in the institute's greenhouse on the Cornell campus. With proper fertilization, lighting, temperature and nurturing, the large-leafed, 14-foot-high plants each produce 100 pounds or more of bananas, said Gregory May, assistant research scientist and part of the research team studying the plant genetics. He said now that researchers know the plants will survive the long Ithaca winters, the team has begun to splice the genes into the banana plants.
Over the next 12 to 18 months, the researchers will conduct feeding studies and generate bananas that express the virus in order for it to be effective as vaccine, said Hugh Mason, BTI assistant research scientist, who is a viral expert.
Elizabeth Richter is the research team's plant genetics engineer, and Nicole Higgs is the cell biologist in charge of regenerating plant tissue to make the project sustainable.
This research may be helpful on the farm, as well. Animals as well as humans could benefit from this technology, Arntzen said.
For example, the technology could be used to deliver vaccines to improve animal disease prevention or for feeding agricultural livestock. Currently, livestock is given antibiotics in their water or through other expensive means to combat a variety of diseases.
BTI is the only major private, independent not-for-profit research institute in the United States focused exclusively on plant research.