Trial tapeworm vaccine takes the bacon

Initial research by a PhD student at the Bioproducts Cooperative Research Centre (CRC) in Melbourne has shown an edible tapeworm vaccine is possible -- for pigs.

Simone Poznanski said she had been working on plant cell culture, and saw there was a possibility of delivering a blocking protein marker in pig feed. "This means that if we could deliver it in feedstuffs, it would stop tapeworm cysts forming, and so stop the disease spreading," she said.

Pig tapeworm (taenia solium) infects some 50 million people in developing countries, and can cause epilepsy and even death if cysts form in critical nervous tissue such as in the brain. The current death rate is estimated at 50,000 people a year, promoted by an oral-fecal cycle where tapeworm is transferred to pigs from human faeces, and then back to humans through infected meat.

Poznanski said pig tapeworm could be treated with drugs, but a simple, prevention-based approach using pig feed was much cheaper, simpler and easier for farmers in less developed countries to use.

"It means there is no need for vaccines and needles, no need to refrigerate drugs and so on. We're looking at a cheap solution to tapeworms that treats infected pigs rather than the people," she said.

The vaccine, which was identified at the Melbourne University Department of Veterinary Science, uses a protein marker on the surface of tapeworm eggs which prevents them from developing into cysts within the pig's body tissue. Although the exact prevention process has not yet been discovered, initial animal trials in Mexico returned 100 per cent results -- no cysts developed in any of the test animals, thus breaking the tapeworm life cycle.

"We are still at the analysis stage, and will hopefully be able to conduct lab trials in the next few months. I've already put [the protein] into arabidopsis, and I am working on a chloroplast in tobacco too," Poznanski said.

"There's a very real possibility that [this] vaccine could completely eradicate these tapeworms, which would be the first time any parasite anywhere in the world has been wiped out," she said.