In a major development in plant-rabies vaccine research in the country, the University of Agricultural Sciences' Department of Biotechnology has received a process patent for using transgenic musk melon as a source of oral vaccine.

While the study on mice is complete, UAS is now working to undertake the study on dogs through an institute- industry tie-up initiative. The agricultural university is now aggressively scouting for a potential industry partner to take on the technology-transfer for vaccine development.

The research team led by Dr PH Ramanjini Gowda, professor, department of Biotechnology and a pioneer in plant based vaccines in India has been working on the same since 2000. The project had received a set back in 2003, when the department of biotechnology refused to clear the study on the grounds that India did not have facility to test plant-based vaccines. In the last year, with a favourable and supportive regulatory environment, DBT turned around to offer a grant of Rs 13.77 lakh to commence the trials on mice and dogs. It is for the trial on dogs that the biotechnology department, UAS led by Dr Gowda is looking for a joint development pact with an industry.

UAS teamed up with National Institute of Mental Health and Neuro Sciences (NIMHANS) for the mice trials to study the efficacy and devise dosages for the plant based rabies vaccine. Although the trials are complete, NIMHANS and UAS are continuing to confirm the effectiveness and ascertain the right dosages for dogs, besides proving that purified protein is better than cell culture vaccine.

The use of genetically altered plants to produce vaccine is gaining importance as it is cost effective and guarantees freedom from human or animal pathogens. This is a study of agro-bacterium mediated transformation of musk melon with a rabies virus (strain ERA) glycoprotein gene (PRGSpRgp).

The presence of the rabies glycoprotein gene in the DNA of transformed melon leaves was confirmed by the PCR amplification. Synthesis of rabies glycoprotein was detected in the transformed musk melon by SDS-PAGE and western blotting. The partially purified, recombinant rabies glycoprotein from a transformed musk melon was injected into intramuscularly and intra- peritonealy into the mice which resulted in the induced anti rabies glycoprotein antibodies. The juice of the musk melon is lyophilized into powder form and converted into pellets and fed to mice. The oral vaccine can now be combined with the anti-fertility drug and used in the mass immunization to control both dog population and rabies.

Key advantages of plant based vaccines are that it prevents protein degeneration. It is economical in the long-run and does not need refrigeration. In terms of cost, it is far cheaper than the cell culture vaccine, which is priced at Rs 300 for 12 doses, and a patient needs five doses as against the plant vaccine, which costs Rs 20 per dose, and five doses will cost Rs 100.

The plants can be easily grown on a large scale and is lucrative for the farming population going by the commercial value. With the platform technology in place plant biotech experts can introduce other genes for various therapies.

The plants are gown at the UAS green house and it was not difficult to source them once the plant gene seeds are available.

Dr Gowda stated that since the study on mice is standardized it has become a platform technology for other plant based vaccines.

UAS team is now also working on the development of GAT 65 using musk melon and ground nut for the developing a type I diabetes drug. Studies are also on for Hepatitis B drug using musk melon, groundnut and coleus forskohlii.

Globally the plant vaccine is a proven technology and Dr. Charles J Arntzen from the Arizona Bio-Design Institute. USA has already developed vaccines for chicks and human trials are on for Hepatitis B with tomato vaccine.