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E. Coli 0157:H7 Vaccine In a Bale

Researchers are working on expressing bacterial proteins in plants with the aim of making edible vaccines. Professor Neil Stewart, a plant molecular biologist from North Carolina State University, was in New Zealand recently and took time to update us on the progress in this area.

The concept is of genetically modifying plants to express large antigenic bacterial proteins to act as oral vaccines. E. coli 0157:H7 has been the focus because of its relative importance to North American food safety. Initially the team has managed to get tobacco plants to express the antigen and is now working on alfalfa as a suitable vehicle. These proteins need to be produced in large quantities and must also be resistant to acid degradation during digestion to stimulate mucosal antibodies.

The genetically modified alfalfa would be grown under secure conditions and processed into hay. Details such as quantity and frequency of dosage are still being studied and could take another two years with five years until release.

So far it looks likely that this approach will succeed in reducing the numbers of E. coli, thus giving some quality control prior to processing. It is not certain that this method will stimulate protective immunity in the targeted animal. Even so this looks like a very easy, inexpensive and humane way to boost immunity in large numbers of animals.

Though this particular project has little relevance to the local scene, similar oral vaccines against other enteric diseases could prove to be a major break-through.