U.S. considering vaccines for chickens as bird flu kills millions

WASHINGTON — The Biden administration, keeping a watchful eye on an outbreak of avian influenza that has led to the deaths of tens of millions of chickens and is driving up the cost of eggs — not to mention raising the frightening specter of a human pandemic — is contemplating a mass vaccination campaign for poultry, according to White House officials.

The bird flu outbreak, which began early last year, is the biggest in the nation’s history, affecting more than 58 million farmed birds in 47 states, as well as birds in the wild. It has already spilled over into mammals, such as mink, foxes, raccoons and bears, raising fears that the virus that causes it, known as H5N1, could mutate and start spreading more easily among people.

Experts at the Centers for Disease Control and Prevention, whose focus is human health, say the risk of a pandemic is low. As a precaution, the agency has sent drug manufacturers flu virus samples that could form the basis of vaccines for people. The CDC is also exploring whether commercial test manufacturers would be willing to develop tests for H5N1, similar to those used for the coronavirus.

Bird flu infections in humans are rare, and transmission of bird flu between humans is extremely rare. Worldwide, there have been nine H5N1 cases reported in people since the beginning of last year, according to the World Health Organization. In Cambodia, an 11-year-old girl recently died from H5N1 and her father was also infected with it, though scientists have not found evidence of humanto-human spread in those cases and the virus was a different version than the one circulating in birds in the United States.

Cases typically involve people exposed to poultry. In the United States, the CDC, in partnership with state and local public health departments, is monitoring people who are exposed to H5N1. As of last week, 6,315 people had been monitored; 163 reported symptoms; and one tested positive, according to Dr. Tim Uyeki, the chief medical officer of the CDC’S influenza division.

Officials at the federal Agriculture Department, which is responsible for the health of farm animals, say they have begun testing potential poultry vaccines and initiated discussions with industry leaders about a large-scale vaccination program for poultry, which would be a first for the United States.

Farm birds are already vaccinated against infectious poultry diseases, such as fowlpox. But an avian influenza vaccination program would be a complex undertaking, and poultry trade associations are divided over the idea, in part because it might spawn trade restrictions that could destroy the $6 billion poultry export industry.

Dr. Carol Cardona, an expert on avian health at the University of Minnesota, said that the fear of trade bans was a huge barrier to the mass vaccination of poultry.

“This is the undeclared war — trade,” Cardona said.

White House officials, speaking on the condition of anonymity to discuss internal deliberations, say that vaccinating poultry is not the only step they are considering. More immediately, they are focused on encouraging poultry farms to prevent transmission of the virus through biosecurity measures like enhanced disinfection procedures for their workers.

Avian influenza experts, however, say they believe the Biden administration should move ahead with a vaccination campaign, in part to reduce the risk of a human pandemic. In interviews, several called for the administration to act quickly.

“My own opinion is under the present circumstances, we should be vaccinating the poultry population of the United States against H5N1 — absolutely,” said Robert G. Webster, an expert in avian influenza at St. Jude Children’s Research Hospital in Memphis, Tennessee. Such a campaign could “prevent the inevitable transmission to humans,” he said.

For President Joe Biden, there are also political considerations at work. Egg prices, which soared in 2022, were 70% higher in January than they were a year earlier. Those high prices have given Republicans another opportunity to attack Biden over inflation just as he is preparing to run for reelection in 2024.

Experts say egg prices could continue rising through the spring,. And the outbreak may worsen in the months ahead as wild birds begin their spring migrations, bringing the virus with them.

The White House officials said they were watching the price fluctuations closely. If a vaccination campaign could provide economic relief for households, Biden would certainly be interested in such an undertaking, one official said.

Experts have long worried that a human-adapted version of bird flu could set off a global pandemic. For that reason, the United States and the world need to be doing more to prepare, said James Krellenstein, an adviser to Global Health Strategies, an international consulting firm.

Krellenstein and Garrett Wilkinson, a policy expert at the nonprofit Partners in Health, examined the world’s readiness for an H5N1 pandemic and identified several “important gaps,” according to a report shared with The New York Times. With a two-dose regimen, the U.S. could need at least 650 million doses of H5N1 vaccine for use in humans.

“While it is extremely important that serious efforts are taken to bring the outbreak in domestic and wild birds under control, the reality of the situation is serious enough that we must be taking more steps to prepare for a possible human outbreak of this virus,” Krellenstein said in an interview.

“We should be viewing this as a live-action fire drill.”