U.S. agency refuses farmers' requests on bird flu vaccine

CHICAGO (Reuters) - The U.S. Department of Agriculture said on Wednesday that it would not allow commercial release of a poultry vaccine to fight the worst outbreak of bird flu in U.S. history because it was not effective enough. The agency said in a notice that additional criteria must be met before a vaccine can be approved for emergency use. The USDA has been developing a vaccine against bird flu and was weighing whether to release it to drug makers for widespread production. Turkey producers in Minnesota, where nearly 9 million birds have been affected by the disease since the beginning of the year, had asked the USDA to approve use of a vaccine to help prevent further infections. The USDA said vaccines "do not meet a suitable level of efficacy." Poultry producers outside Minnesota had objected to approval of a vaccine out of concern that its use would further limit international trade. Major importers of U.S. poultry and poultry products have already cut shipments in the $5.7 billion export market due to the outbreak. USDA said "additional outreach with trading partners will be required to avoid significant market disruptions." Nationwide, almost 45 million birds have been killed or are due to be killed as a result of the outbreak. (Reporting by Tom Polansek; Editing by Toni Reinhold)