Edible vaccines closer to market

Transgenic plant technologies could lead to a revolution in vaccine production and manufacture; should plant-based vaccines prove effective in clinical trials, this will drive licensing activity between key vaccine players and companies with relevant intellectual property.

Transgenic plant technologies could lead to a revolution in vaccine production and manufacture and, should plant-based vaccines prove effective in clinical trials, this will drive licensing activity between key vaccine players and companies with relevant intellectual property, according to Datamonitor.

One of the pioneers of the transgenic plant technology used in edible vaccines, Axis Genetics, folded in 1999 after failing to raise enough cash to continue operations. At the time, the company blamed investor timidity in the face of growing public resistance to genetic modification of plants.

However, since then, plant-based vaccines are now edging closer to commercialisation, according to Datamonitor, which cites a review article in the International Journal for Parasitology. The market researcher says that Prodigene is currently leading the way in developing plant vaccine technology and, in 2001, the company's oral viral vaccine patent was voted one of 'five patents that will transform business and technology' by MIT Technology Review magazine.

"This recognition reflects the huge potential of plant-based 'edible' vaccines to revolutionise the vaccine sector," according to Datamonitor, which notes that German scientists have also developed GM tomatoes that could be used to deliver vaccines and antibodies.

The convenience of delivery is the most obvious benefit of these systems, reducing the pain and distress associated with traditional injectable vaccines and potentially increasing compliance with immunisation schedules. Physicians could potentially hand out corn-based vaccine snacks to children, while access to adult and elderly immunisations could be increased.

And vaccine delivery through crops could have significant benefits, most notably in the developing world. Vaccines could be grown from seed and then freely distributed without the need for trained medical staff at any stage. Implementation of such schemes would probably require initially high expenses in terms of education and training, Datamonitor points out, but thereafter would be relatively cheap.

"Should such schemes become commonplace the emphasis of vaccine manufacture could shift away from pharmaceutical companies towards companies that develop GM crops," it added.

Plant-based systems have obvious advantages for existing players, in terms of reduced production costs, ease of scale-up and the previously mentioned delivery advantages. Not only are raw material and purification demands reduced (corn produces proteins more cost-effectively while plant and animal pathogens are distinct, reducing the potential for cross-infection), but transportation, storage and administration costs could also be lowered.

"Key vaccine players could benefit significantly from these developments and should monitor continued progress very carefully. Should human trials of such vaccines prove successful, there is likely to be significant licensing/partnership activity between vaccine players and companies holding intellectual property for transgenic plant technology," said Datamonitor.