The past year has already been a bad one for H5N1, the virus that causes bird flu. And it’s about to get worse as wild birds complete their spring migrations in the northern hemisphere in the coming weeks, experts warned.
Where birds go, H5N1 goes too. All along bird-migration routes, which criss-cross North America, Europe and Asia, infection risk could increase. Not only for other birds—including domestic flocks of chickens, ducks and turkeys—but also for the growing number of mammal species that have caught bird flu. Foxes. Bears. Sea lions. Minks. Pigs. “Increased migration is definitely a concern,” James Lawler, an infectious disease expert at the University of Nebraska Medical Center, told The Daily Beast.
The risk to people could spike, too. The 2022-2023 bird flu outbreak has already claimed at least one human victim, in China last year. At least five other people have caught the virus and survived.
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This spring, more people could come into contact with infected animals. Epidemiologists are worried that people might start spreading bird flu to other people, too—raising the specter of a possible human bird flu pandemic.
But even as billions of birds take flight, authorities are at an impasse. The one strategy that might make an immediate dent in H5N1’s spread—the mass-vaccination of domestic chickens, geese, ducks and turkeys—faces some profound logistical obstacles.
Last year saw a period of overlapping viral outbreaks—COVID, monkeypox, even polio—so you might not have noticed the bird flu outbreak that seems to have begun in mid-2021 but really accelerated in January 2022. First, an 80-year-old British man came down with the bird flu after exposure to wild ducks. Next, the U.S. Department of Agriculture detected H5N1 in domestic chicken flocks in the United States.
Infections spread far and wide during the 2022 bird migration season. A year later, 54 countries had detected H5N1 in wild birds or, in some cases, certain mammal species. In the United States alone, bird flu has been detected in 47 states, according to the U.S. Centers for Disease Control and Prevention. Almost 60 million wild and domestic birds have been affected in the U.S., the CDC reported.
In 2022 alone, the U.S. poultry industry culled—that is, killed—no fewer than 50 million chickens, geese, ducks and turkeys in an effort to slow the virus’s spread. Wondering why egg prices spiked last year? A sharp reduction in domestic chicken flocks is the main reason. In other words, blame bird flu.
Egg prices in the U.S. have finally begun to fall as the industry recovers from the 2022 culls. The average price for a dozen eggs peaked at $5.20 late last year. It dropped fast in January and February to an average of around $2.40. But now the 2023 bird migration threatens more viral spread and potentially more bird deaths. The price of eggs is inching up again.
Pricey eggs aren’t the biggest problem. While H5N1 can infect people who come into close contact with infected birds, it hasn’t yet spread from person to person. Absent human spread, there’s almost no chance of runaway bird-flu outbreaks in people. After all, most of us never come into contact with infected birds. “Some farmers and zoo workers may be at risk, but those interaction events are going to be limited,” Tony Moody, a professor of Immunology at the Duke Human Vaccine Institute, told The Daily Beast.
But every H5N1 infection, in animals or people, is an opportunity for the virus to mutate. And it might not take a huge genetic leap for the H5N1 to become a truly human virus, and spread among family, friends and neighbors just like human influenza, COVID, monkeypox and a host of other viruses.
Maybe. “We just don’t know enough to accurately predict” the risk of a major bird flu mutation, Lawler stressed.
A big outbreak of bird flu in pigs would be a red flag, Moody said. “They tend to be the ones implicated in generating new strains with a higher risk of human-to-human spread.”
What’s especially scary about H5N1 is that it’s highly lethal. Where human flu kills less than 1 percent of infected people, and COVID kills around 3 percent, bird flu kills more than half of the people it infects. We have every incentive to prevent the virus from becoming a human virus.
But experts and officials disagree on how to do that. Widespread vaccination would help, of course. But while several human bird flu vaccines are in development, none are ready for human trials—to say nothing of being ready for approval by the U.S. Food and Drug Administration or regulators in other countries. Even under the most optimistic scenario, it’ll be years before people can get a bird-flu jab.
There are already vaccines for birds, but they only prevent severe disease. They don’t prevent the virus from spreading flock to flock. Better bird vaccines that do prevent transmission have been in development for a few years now. Last month, the Department of Agriculture announced it would test the first of these new vaccines. But it’s not clear how long testing and authorization might take.
Nor is it clear exactly how the feds would administer the vaccine. It’s impractical to innoculate wild birds, of course, but even farm flocks pose a challenge. There are 2 billion domestic chickens in the U.S. and hundreds of millions of geese, ducks and turkeys. No one has figured out the right strategy for dosing them.
Do authorities target domestic flocks closest to wild birds’ migration routes? Do they try to dose domestic birds before possible exposure to the virus? Do they wait until after they detect the first infection in a particular flock? “From vaccine development, to production timelines, to dissemination to flocks, there are many factors that make implementing a vaccine strategy a challenge and it would take time to deliver an effective vaccine,” a USDA spokesperson told The Daily Beast.
Even if the Department of Agriculture swiftly tests and approves a bird vaccine, it might not have any idea how to actually deploy the vaccine. Adding vaccine to the birds’ feed “might work,” Moody said. But it’s going to take a lot of experimentation to figure it out.
All that is to say, we’re probably not going to solve our bird flu problem this year. So as those billions of migratory birds take flight this spring, all we can do is hold our collective breath… and hope for the best.
