The U.S. Department of Agriculture is looking into vaccines as an option to protect poultry against deadly bird flu, the agency's chief veterinary officer said as the country faces its worst outbreak since 2015.

Supporters say vaccines could help keep poultry alive, prevent financial losses and control food costs, though shots would be too late to stop the current outbreak that has wiped out 22 million chickens and turkeys in commercial flocks since February.

Previously, the United States has eschewed vaccines, worried that importers will ban U.S. poultry shipments because they cannot distinguish infected birds from vaccinated ones. The United States is the world's second-largest poultry meat exporter a major egg producer, with shipments reaching $4.2 billion in 2020.

However, the USDA's Agricultural Research Service is investigating the potential for a vaccine that could be distinguished from the wild type of virus spread to poultry, Chief Veterinary Officer Rosemary Sifford said in an interview.

"We feel strongly that if we could develop a vaccine like that, that would have less of a trade impact," Sifford said. Researchers estimate that would take at least nine months to develop, she said.

Bird flu has hit poultry in Europe and Asia in addition to North America, and Sifford said the USDA is working with other countries on options for vaccines. Trading has suffered, as importers like China have blocked imports from more than a dozen U.S. states with outbreaks.

Though vaccines could protect poultry, some producers worry they would be cost prohibitive for chickens raised for meat, which only live about five to seven weeks.

Still the International Poultry Council, an industry group representing producers worldwide, is reviewing the possibilities, said Jim Sumner, a council member and president of the USA Poultry & Egg Export Council.

"We recognize that in some extreme cases of severe outbreaks, maybe vaccination needs to be considered as an option," Sumner said.

• Alberta's chief medical officer Hinshaw tells court rights were violated for the greater good, during pandemic
• Canadian woman dies of complications after receiving AstraZeneca vaccine; chief medical officer confirms death linked to jab

• Suspect charged in Gretchen Whitmer kidnap plot had anarchist flag, hates police
• Suspects claim undercover FBI informants played key role in plot to kidnap Michigan governor: Accuse govt of entrapment
• FBI agent tried to profit financially from knowledge of Michigan governor 'kidnapping' plot, defense lawyers claim
• FBI fires lead agent in Gov. Whitmer Kidnapping case
• Whitmer kidnapping plot suspects seek dismissal of charges, say FBI invented conspiracy
• FBI Using the Same Fear Tactic From the First War on Terror: Orchestrating its Own Terrorism Plots

• Remember the plot to kidnap MI Gov. Whitmer that the FBI foiled? Yeah, the FBI apparently helped hatch it
• Suspects claim undercover FBI informants played key role in plot to kidnap Michigan governor: Accuse govt of entrapment
• 'Deny and accuse somebody else': FBI instructed informant in Michigan governor 'kidnap' plot to slander another man, report says
• High pressure tactics in FBI coverup surrounding Whitmer case
• FBI agent tried to profit financially from knowledge of Michigan governor 'kidnapping' plot, defense lawyers claim

• Whistleblower who turned in Hunter's abandoned laptop reveals he has 450GB of DELETED material - and has fled to Switzerland fearing retaliation from White House
• Need for a special counsel in Hunter Biden's case has grown urgent
• Biden's 'absolute' defense of Hunter leaves media and Justice Department in a muddle
• Former prosecutor on Hunter Biden: 'Anybody else would have been indicted already'
• Hunter laptop story confirms: Rein in Big Tech or cease to be a free people
• The media avoided the ties between Joe Biden and Hunter's laptop
• CIA veteran who signed Hunter Biden laptop letter says he sarcastically claimed credit for 2020 election
• Hunter Biden's laptops are now an active national security threat