The U.S. Department of Agriculture’s (USDA) chief veterinarian, Dr. John Clifford, said the agency is preparing for the likelihood the avian influenza virus will return this fall, according to Brownfield Ag News.

“What we’re planning is a worst-case scenario that every major poultry-producing state in this country, for layers, broilers and turkeys, could be affected,” Clifford says.

The veterinary services division of the Animal and Plant Health Inspection Service (APHIS) has hired more than 450 temporary workers, including 300 veterinary first-responders, in preparation for possible outbreaks this fall.

Although there are still questions about the effectiveness of vaccines and the effects their use could have on the export market, Clifford said USDA is developing a potential vaccine strategy.

“Should we decide to use vaccines to address the outbreak, we’ll have the systems in place to do so,” he said.