CHICAGO, March 23 (Reuters) - The U.S. government is developing a vaccine to protect poultry from new strains of avian flu that have recently killed birds from Arkansas to Washington state.
Within two months, scientists at a U.S. Department of Agriculture (USDA) research lab in Georgia will test the vaccine on chickens. to see how well it prevents birds from getting sick and dying of the virus. The government has linked its spread to wild birds that carry it and then infect domestic flocks.
Progress toward creating a vaccine has not previously been reported. The H5N8 and H5N2 flu strains have infected birds in eight states since December, prompting key overseas buyers to limit imports of U.S. poultry.
The world's biggest poultry producers, including Tyson Foods Inc and Sanderson Farms Inc, have increased biosecurity at farms to protect their flocks.
The government has no plans to distribute the vaccine yet. Instead, the United States will continue to cull infected flocks and test nearby birds to prevent the virus from spreading.
The United States is developing the vaccine in case it needs a countermeasure to the containment strategy, said T.J. Myers, associate deputy director of surveillance, preparedness, and response services for the USDA's Animal and Plant Health Inspection Service. The agency will ultimately decide whether to release the vaccine.
The new strains have been found in wild birds that can carry the virus on migratory routes so "there's really no way to predict where the next case might be," Myers said. Vaccinating all poultry nationwide is not considered practical or necessary, he added.
U.S. development of vaccines in response to lethal viruses is routine, according to the USDA. Still, the effort illustrates the government's aggressive response to the disease, which can kill nearly every bird in an infected flock within 48 hours.
Use of a vaccine may be considered if avian flu "gets to the point where we cannot contain it," said Mark Jackwood, head of the University of Georgia's Department of Population Health.
The U.S. Southeast Poultry Research Laboratory, which is working on the new vaccine, tested the effectiveness of an existing vaccine in fighting the strains. It did not perform as well as scientists wanted, Director David Swayne said.
Separately, the U.S. Centers for Disease Control and Preventions is preparing a team to respond if birds transmit the flu to humans, said Michael Jhung, a medical officer for the agency's influenza division. The risk for human infection is considered low. (Reporting by Tom Polansek; Editing by David Gregorio)