Malaria and cholera take devastating tolls in the developing world. Mosquito-borne Malaria kills more than 1 million people annually and no vaccine currently exists. Cholera, a diarrheal illness
that is common in developing countries, can be fatal and the lone vaccine is too expensive to prevent outbreaks after floods.  Despite the challenges posed by the malaria and cholera, University of Central Florida biomedical researchers say they have developed what may be the first low-cost dual vaccine for both

The UFC team genetically engineered tobacco and lettuce plants to produce the vaccine. Researchers gave mice freeze-dried plant cells (orally or by injection) containing the vaccine. They then challenged the mice with either the cholera toxin or malarial parasite. Untreated rodents contracted diseases quickly, but the mice who received the plant-grown vaccines showed long-lasting immunity for more than 300 days (equivalent to 50 human years).The results are published in this month's Plant Biotechnology.

Clinical trials are needed, and the team is hopeful that the results with mice will translate to humans. It could be yet another example of plants delivering life-saving medicines.

Researchers also stressed that producing vaccines in plants is less expensive than traditional methods because it requires less labor and technology."We're talking about producing mass quantities for pennies on the dollar," said lead scientist Henry Daniell. "And distribution to mass populations would be easy because it could be made into a simple pill, like a vitamin, which many people routinely take now. There is no need for expensive purification, cold storage, transportation or sterile delivery via injections."

"I'm very encouraged because our technique works well and provides an affordable way to get vaccines to people who need them most and can least afford them," Daniell concluded.

Citation: Davoodi-Semiromi et al., 'Chloroplast-derived vaccine antigens confer dual immunity against cholera and malaria by oral or injectable delivery', Plant Biotechnology, December 2009, Volume 8 (2), 223 - 242; doi: 10.1111/j.1467-7652.2009.00479.x