Russian and U.S. researchers have developed genetically modified tomatoes that contain an edible vaccine that could challenge HIV and the hepatitis B virus (HBV) in humans.

Researchers at Russia's Siberian Institute of Plant Physiology and Biochemistry used the soil bacterium Agro-bacterium tumefaciens to shuttle a synthetic combination of HIV and HBV DNA fragments into tomato plants. These include fragments of genes for various HIV proteins and the gene for an HBV protein called HBV surface antigen, according to a report on the New Scientist website on Thursday.

The tomato plants then manufacture the proteins and, like the oral polio vaccine, when the tomatoes are eaten, these proteins prompt the body to create antibodies against the viruses.

Mice fed a solution containing the tomatoes in powdered form developed high levels of antibodies in their blood to both viruses, the researchers said.

The vaccine does not need to be refrigerated or injected, which are big advantages in poor countries, the report said, quoting researcher Rose Hammond of the U.S. Agricultural Department which is collaborating with the Russian researchers.

The aim is to create affordable vaccines for HIV and the HBV that could be easily grown and processed in the countries where they are most needed.

If the tomato-based vaccines work in humans, they could be given in tablet form, since giving people the tomatoes directly would make it difficult to control how much protein they received, the researchers said.

Source: Xinhua