Virologists hatch plan to beat bird flu

Virologists at Cambridge University have teamed up with scientists from the Roslin Institute to create genetically modified chickens that can resist the lethal H5N1 avian flu virus, writes Yfke van Bergen.

The influenza virus is an accomplished species hopper and has already jumped from chickens to humans. As a result, scientists are looking into ways to eliminate the threat of a human pandemic.

While flu-resistant chickens will not appear on poultry farms in time to avert the current crisis, they could be the key to preventing future avian flu pandemics.

Laurence Tiley, a molecular virologist working at the Centre for Veterinary Science in Cambridge, said that the team was working on three strategies to prevent the virus replicating in chickens.

Many chicken breeds carry a defective version of an antiviral protein called Mx. The team hopes that by "repairing" this defunct protein it can restore chickens' ability to ward off the H5N1 virus. But if that strategy fails, scientists plan to use "decoy" genetic segments that trick the virus into replicating them rather than the virus.

Attempts to control the H5N1 virus epidemic in South-East Asia by slaughtering millions of chickens have been unsuccessful so far.

Dr Tiley said: "Developing flu-resistant chickens has clear benefits for human health and animal welfare, as we wouldn't have to slaughter chickens around the world."

He said that it would be another year before the Veterinary Laboratories Agency could test whether the chickens were resistant to avian flu. He added that it would take another four to five years before enough transgenic birds could be bred to replace the world's broiler chicken population.