The U.S. Department of Agriculture is considering a potential plan to vaccinate poultry against bird flu for the first time that includes evaluating how it would affect exports, the agency told Reuters this week.

The actions advance the government’s assessment of a vaccine after the USDA received proposals on usage from associations representing egg and turkey producers whose farms have been devastated by the virus. Nearly 175 million chickens, turkeys and other birds have been culled in attempts to contain outbreaks since 2022 in the nation’s worst animal-health emergency.

The USDA pledged to spend up to $100 million on research into vaccines and other therapies to combat bird flu after prices spiked.