Chicken eggs to hatch snake anti-venom

NEW DELHI: Indian scientists have discovered that chicken eggs can become a source of molecules to treat snake bites. The method will provide relief to horses which undergo painful tests for collection of snake anti-venom.
The process of extracting snake anti-venom from horses had come under scrutiny after animal activists, led by former Union Minister Maneka Gandhi, protested about cruelty to horses.It also led to a shortage of snake anti-venom in the country, Prof P.V. Subba Rao of the Vittal Mallya Scientific Research Foundation, Bangalore, told a biotechnology conference here on Friday.
“The process we have developed is likely to find favour among animal activists. The work began about two years ago and has been supported by the Department of Biotechnology,� Rao said.
“Table leghorn chickens are made to produce anti-venom antibodies which get concentrated in the egg yolk,� he said, and added that for this, about 12-week-old birds are injected sub-lethal dose of venom intramuscularly. They are given a booster dose after two to three weeks. The birds start laying eggs containing anti-venom antibodies from the 22nd week.
The process did away with the painful step of extracting blood from horses repeatedly. Though a sub-lethal dose of the venom was given to horses, it sometimes led to toxicity, he said.
The new process is also an improvement in terms of quantity — one bird lays five eggs in a week or 240 eggs per year. One egg has about 50-100 mg of antibodies called IgY, 10 per cent of which, about 5-10 mg, has anti-venom activity.
The antibodies produced by 1 litre of horse blood could be obtained from just 50 eggs, he said, adding the anti-venom produced in eggs has been tested on mice.
While one lethal dose of venom leads to the death of the animal in 12 hours, animals get 100 per cent protection if they get the appropriate dose of anti-venom within half-an-hour of the venom injection, Rao said.
The problem with the anti-venom produced in horses is that it carries other proteins which sometimes cause allergic reactions, kidney failure and serum sickness in people. No such problems are expected in the anti-venom produced in eggs, he said.
“We are still improving the technology. At the moment we have prepared anti-venom for different snake species. Snakes cause toxicity either by affecting the nervous system or the heart. We are now trying to prepare a combination which will be effective against both kinds.’’
A welcome step in that it reduces suffering for the horses. Animal lovers, however, will hope that soon it will be possible to make anti-venom in laboratories without inflicting pain on any living thing.