A worker at the Harare tobacco market in Zimbabwe runs a quality check. Photograph: Nadine Hutton
Scientists in Southern Africa may be able to rescue regional tobacco agriculture without compromising on the health of our lungs — by growing desperately needed antibodies in tobacco leaves.
GreenPharm — a spin-off biotechnology company based at the Council for Scientific and Industrial Research (CSIR) — is investigating a safer and cheaper rabies treatment using genetically modified tobacco.
When someone is bitten by a rabid animal, the ideal treatment is wound cleaning, neutralisation of the virus with an injection of antibodies and activation of the immune system with the rabies vaccine.
But rabies antibodies are so expensive that few supplies exist in developing countries, including most of sub-Saharan Africa.
Enter Zimbabwean plant biotechnologist Rachel Chikwamba, a research fellow at CSIR biosciences unit and principal investigator at GreenPharm.
Her antibody drug Rabivir ”is potentially cheaper than existing vaccines as it will be extracted using relatively simple technology from tobacco leaves, which are cheap to grow and can guarantee a reliable supply”, says Chikwamba.
She says Rabivir is also likely to be safer than current antibodies. Samples of human or equine antibodies can be contaminated with potentially fatal pathogens such as hepatitis, ”especially in Africa where serious blood-borne infectious diseases are prevalent”.
The drug is undergoing animal tests — due to be completed by the end of February — on infected mice, says Ereck Chakauya, a University of Zimbabwe biotechnologist and project manager at GreenPharm.
Earlier laboratory tests indicated the antibodies were effective against the major African rabies strains.
If permission for human testing is obtained eventually, CSIR plans to scale up production to supply the antibody to members of the Southern African Development Community. But Chikwamba warns: ”It’s early days yet.”
The tobacco-nurtured rabies antibodies could also help make cheaper diagnostic tests for rabies and help technicians capturing samples of the rabies virus in the laboratory to analyse their genetic evolution, says Chikwamba. — SciDev.Net