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Want a Bird Flu-Free World?

August 13, 2015
"So far, the USDA has spent $500 million helping farmers recover from the losses." ~ Tamar Haspel re Avian Influenza.

Since December 2014, there have been 73 counties in the U.S. and two Canadian provinces with confirmed cased of the bird flu (APHIS, 2015; and Canadian Food Inspection Agency, 2015).

"The total number of U.S. birds affected stands at 45 million, and includes 37.5 million chickens and 7.4 million turkeys; economically the bird flu impacts as many as 233 thousand poultry farms in the U.S. The ongoing avian influenza outbreak has resulted in the depopulation of more than 45 million birds," according to Newton and Kuethe at the University of Illinois.

What if the solution to avian influenza could be found in the chicken itself? It could be. In her piece, "Want a Bird Flu-Free World? Consider Breeding Resistant Birds," Tamar Haspel highlights the work begin done by a team of researchers in the UK who are working to genetically modify a bird (chicken) so it doesn’t pass the virus on to other birds:

The flu was first detected in backyard flocks in the Pacific Northwest at the end of last year...Most of those birds are egg-layers, and the retail price of eggs has been hovering around $2 a dozen since June, up from $1.22 in May. 
...It’s extremely easy, though, for birds to catch it from other birds. And that’s the problem. If one bird gets the virus, the entire flock is doomed.

That’s where the GM chicken comes in.

Laurence Tiley, a virology specialist at the University of Cambridge who helped develop the bird, explains that the scientists modified the chicken in such a way as to fool the virus into not replicating.

Here’s how it works: The avian flu virus has the ability to replicate itself. It does this by using an enzyme (polymerase) that recognizes a particular sequence on its genome. When the enzyme finds that sequence, it attaches itself, and duplicates it.

The modified bird (Isa Brown chickens, to be precise) has a decoy—a fragment of RNA with the sequence the enzyme is looking for. On its own, the fragment is harmless and inert; it doesn’t affect the bird. But when the bird picks up the flu virus, the virus’s enzyme finds the decoy and duplicates it instead of the virus. The infected bird dies (and Tiley says they’re still trying to pinpoint exactly why), but doesn’t pass the virus on to other birds.

While the bird is still in the lab, and not yet in production, Tiley says it wouldn’t take much to get there. The scientists would have to introduce the modification in a breed of bird used commercially (Tiley estimates that would take 18 months), and then establish a flock from that founder bird (another four years). The decoys are not protected by patents, and when I asked Tiley about ongoing costs, he said, “none.”...

The GM chicken does an end-run around some of these problems (although trading partners who don’t want vaccinated birds may balk at GM birds, too), with the added benefit that the RNA decoy works for all flu strains, because the sequence the replicating enzyme latches on to is common to all of them. Which means that the modification’s usefulness isn’t limited to chickens; it can work in any animal that gets the flu.

“The next animal it makes sense to do is the pig.” says Tiley. It’s a leap of faith, of course, but imagine a world where all pigs and chickens are bred with the RNA decoy. It certainly wouldn’t be a guarantee against human flu pandemics, “but it could help,” says Tiley.

What stands between the GM chicken and commercial implementation is opposition to using genetic modification techniques to mess with animals, a concern Tiley hears often. “The anti-GM community isn’t so much worried about a health risk, but concerns of animal exploitation and tinkering with nature,” he says. “It’s difficult to come up with any assurance that they’re going to accept.”

Tiley doesn’t forsee the GM chicken being introduced into the UK or the U.S. any time soon. “The most likely way these types of animals will be introduced is in countries that have more pragmatic views of GM,” he says: “China, for example.”

A solution to a problem that works in the lab doesn’t always work in the world, and there’s obviously more research needed to figure out the extent to which a genetically modified bird can help protect our poultry flocks’ health. But the gut-wrenching slaughter and tremendous expense that kept making the news week after week this spring should open us up to the possibility.