The US Department of Agriculture (USDA) is "18 months or so" away from identifying a vaccine for the current strain of avian influenza and is developing a process to distribute it, Reuters reported, citing Agriculture Secretary Tom Vilsack on Wednesday.

USDA has found avian influenza in eight commercial flocks and 14 backyard flocks so far this year, affecting 530,000 poultry, according to agency data.

More than 81 million US poultry and aquatic birds have been killed by avian influenza across 47 states since January 2022, according to the Centers for Disease Control and Prevention.

"We are probably 18 months or so away from being able to identify a vaccine that would be effective for this particular [avian flu] that we’re dealing with now," Vilsack said at a Congressional hearing.

USDA plans to discuss poultry vaccinations with trading partners, amid concerns that other countries could restrict imports of vaccinated US poultry, Vilsack said.

The World Organization for Animal Health in May said governments should consider bird flu vaccinations for poultry to prevent the spread of the virus from turning into a pandemic.

The US government said last year that a decision by France to vaccinate ducks against avian influenza will trigger restrictions on imports of French poultry.