GM plants take the sting out of scorpion venom
By Clare Pillinger
A REVOLUTIONARY new vaccine using tobacco plants to combat scorpion stings is being developed by a British plant geneticist to help to save the lives of hundreds of children.
The latest available figures show that almost 250 children, the majority under seven years old, died as a result of scorpion stings in Brazil between 1990 and 1993. During the same period, there were 22,000 reported cases of scorpion stings with a mortality rate of 1.1 per cent.
Now researchers at Durham University are pioneering a cheap and easy way to produce vaccine for large-scale immunisation of children living in Belo Horizonte in Minas Gerais, a city plagued by the tiny, highly toxic, yellow scorpion, Tityus serrulatus. In the long term, it may even be possible to produce the vaccine in a fruit that children will eat regularly, thus setting up an immunity to the scorpion stings.
At present, the only treatment is a serum derived from horses injected with the venom. The protein that is the vaccine is found in scorpion venom only in very small concentrations. Large-scale immunisation is therefore not possible - there is only enough in the world to treat about 12 people.
But now biologists have produced a man-made gene to make the vaccine, which can be stored and used for mass immunisation. Dr Kieran Elborough, the research group leader in the Biological Sciences Department at the University of Durham, said: "We have made a man-made gene that makes large amounts of the vaccine in plants. The beauty of this scheme is that the tobacco plants can be grown in laboratories, without any risk of foreign genes getting into other plant species, at the same time producing a vaccine to help to save hundreds of lives in a country that cannot afford expensive medical facilities."