The Burrill Report


Outbreaks of bird flu in late 2003 and 2004 carried a devastating economic toll to South-east Asia where the infections were worst. By mid-2005, The World Bank reports, more than 140 million birds had died or been destroyed and the poultry industry suffered losses in excess of $10 billion. An outbreak that turns into a human pandemic, could cost the global economy about $1.25 trillion. Some scientists, aware of the threat, are taking a new approach to containing the spread of the disease.

Forget about anti-virals and vaccines. Researchers at the Universities of Cambridge and Edinburgh have decided a better solution is to simply build a better chicken. To that end they say they have genetically modified chickens to prevent them from being able to spread bird flu.

The study, published in the journal Science, reports that scientists successfully developed genetically modified chickens so they do not transmit bird flu to other chickens. They say the genetic modification has the potential to stop bird flu outbreaks spreading within poultry flocks. It could also reduce the risk of bird flu epidemics leading to new flu virus epidemics in humans.

“Preventing virus transmission in chickens should reduce the economic impact of the disease and reduce the risk posed to people exposed to the infected birds,” says Laurence Tiley, senior lecturer in molecular virology from the University of Cambridge’s Department of Veterinary Medicine. “The genetic modification we describe is a significant first step along the path to developing chickens that are completely resistant to avian flu.”

He says the birds are intended for research purposes only and not consumption.

To produce these chickens, the Cambridge and Edinburgh scientists introduced a new gene that manufactures what they described as a “decoy” molecule that mimics an important control element of the bird flu virus. The replication machinery of the virus is tricked into recognizing the decoy molecule instead of the viral genome and this interferes with the replication cycle of the virus.

The genetic modification doesn’t prevent the transgenic chickens from getting infected or sick, but they do not transmit the infection to other chickens kept in the same pen. This was true even when the other birds surrounding an infected transgenic chicken were not ones that had been genetically modified.

Helen Sang of The Roslin Institute at the University of Edinburgh noted that the effort reflects the potential of applying genetic modification to animal health as well as food security in ways that animal breeding simply cannot.

Of course, there will likely be consumer resistance to eating genetically modified animals. The U.S. Food and Drug Administration in September held three days of hearings about Massachusetts-based AquaBounty Technologies’ desire to begin selling salmon that is genetically engineered to grow twice as fast as normal salmon. The FDA hasn’t rendered a decision, but agency staff in a report prior to the hearing said genetically engineered salmon is as safe to eat as normal salmon. Some members of the FDA’s Veterinary Medicine Advisory Committee, however, thought more data was needed to make that determination.

Developing a flu resistant chicken is just a start. Imagine chicken genetically modified so it has eight wings or four legs. A single appetizer could be crafted from one bird so families could sit down to dinner and not fight over who gets the drumsticks. My guess is that once researchers can genetically modify chickens to produce 11 secret herbs and spices, we can overcome consumer reluctance.


January 14, 2011
http://www.burrillreport.com/article-building_a_better_bird.html