Transgenic chickens get bird flu without passing it on

: Image via Wikipedia

Researchers have engineered a new type of chicken

Researchers have engineered a new type of chicken that might help prevent the spread of bird flu—a worrisome virus that has already caused extensive economic harm on farms, especially in Asia, and that could lead to a pandemic in humans.

Many farmers have gone to great lengths to prevent a poultry-based pandemic, but the newest results are “a significant first step along the path to developing chickens that are completely resistant to avian flu,” Lawrence Tiley, a molecular virologist from the University of Cambridge’s Department of Veterinary Medicine, said in a prepared statement.

Usually kept in close quarters, chicken flocks are prone to rapid spread of viruses. The new study, published online January 13 in Science, describes a genetic trait that seems to prevent chickens from sickening their feathered neighbors, which could also reduce the risk that the flu would jump to humans, as has occurred with sporadic cases of H5N1 since 1997.

The gene makes “an innocuous decoy RNA” that closely resembles the viral genome. This decoy molecule tricks the virus into replicating it instead of producing more viral material. Incorporating the gene that makes this molecule into poultry, the research team found that although birds can still get—and even die from—the flu, they do not pass it on to nearby non-transgenic chickens.

“The decoy mimics an essential part of the flu virus genome that is identical for all strains of influenza A,” said Tiley, who co-authored the new study. The RNA that the gene generates is so general that it should work against all forms of the flu—year after year—rather than needing to be reconfigured like the influenza vaccines currently administered to chicken flocks, the researchers concluded.