And four other burning bird flu questions, answered.
by Jess Craig
Jan 26, 2025, 3:00 AM PST
Egg shortage signage is displayed on partially empty shelves at a Sprouts Farmer’s Market grocery store in Lawndale, California, on January 2, 2025.Patrick T. Fallon/AFP via Getty Images
Jess Craig is a Future Perfect fellow covering global public health, science, and environment. Previously, she worked as an infectious diseases epidemiologist and global health security adviser supporting various US government agencies, multilateral organizations, and private research institutes.
Bird flu is surging in the US again and has, once again, sent egg prices skyrocketing. Nearly 13 million birds have been infected or culled in the past month alone, contributing to shortages. A carton of eggs today costs more than $4 on average, up from about $2.50 a year ago.
Prices aren’t the only thing making headlines — the virus has recently taken a human life, too. After nearly three years of warnings from leading public health and animal agriculture experts that bird flu was becoming a threat to human beings, Louisiana health officials reported earlier this month that an individual died from the virus, the first reported human death in the US from bird flu.
This particular strain of bird flu, H5N1, has been circulating in the US and infecting poultry since February 2022. So far, millions of birds have been infected or were culled to prevent further spread. But, as Vox reported previously, the concern has always been that this strain could jump from birds, then to another animal, and then to humans, and evolve along the way into something much deadlier to humans.
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Last March, the virus made its way to US dairy cows. About a month later, Americans began getting infected in greater numbers — the majority of those infected, health officials say, were exposed to commercial cattle or poultry farms. Today, nearly 1,000 cattle herds across 16 states have been affected, according to the US Department of Agriculture (USDA).
The deceased Louisiana patient, however, was infected by backyard poultry wild birds. The individual was older than 65 years old and had underlying medical conditions, which likely increased their risk for severe disease and death, as it does for conventional flu.
This case brings the total number of documented human infections in the US to 67. Human infections have been reported in 10 states so far, but most cases have occurred in California, where the governor declared a state of emergency in December.
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As much as the death set off alarm bells, the risk to most people in the US from bird flu remains very low. Humans aren’t catching bird flu from one another right now. That could always change, though. The H5N1 virus could mutate in some way that makes it easily transmissible between humans. This is how a flu pandemic would begin.
And as long as that possibility remains, it’s easy to feel as though not enough is being done to prevent the possibility of another terrible pandemic, especially when influencers are touting raw milk as a potential, natural “medicine” for various ailments (it’s not) or when official government responses feel unclear or insufficient. (There is some truth to that.)
From egg prices and vaccines to pandemic potential and disease monitoring, here are five answers about the ongoing response to bird flu.
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- Yet another person got bird flu. Now should I freak out?
- Could bird flu cause a human pandemic?
- Why aren’t we vaccinating birds against bird flu?
How is the government responding to bird flu — and is it doing enough?
Bird flu mostly spreads among wild and domestic birds, but the virus sometimes does spill over and infect other animals. In the past three years, bird flu has infected cows, seals, bears, dogs, cats, and a number of other mammals.
As with any major disease, the Centers for Disease Control and Prevention (CDC) are working alongside state agencies to track cases in humans. But because most people eat animals for food, there are two other key players involved: the USDA and the Food and Drug Administration (FDA).
The USDA leads federal efforts to monitor and contain bird flu among farm animals, live bird markets, backyard flocks, and wild animals. The agency develops biosafety and biosecurity standards to prevent the spread of bird flu, and then assists state agencies and commercial farmers to implement those measures. In addition, the agency runs a bird flu surveillance program that involves trapping wild birds, collecting samples from them, and testing them for H5N1 and other pathogens. Wild birds are a reservoir for bird flu, meaning that the virus is normally spread among them and from there spills over to infect domestic birds and other mammals.
Farmers and poultry or cow owners who suspect their flock or herd is infected with bird flu can report the cases to the USDA and to state animal health officials or to their veterinarian, who can then report the cases up the chain. The USDA has a network of laboratories that tests samples from flocks and herds across the country for H5N1 and other pathogens.
But while this might seem like the USDA has broad reach to closely monitor poultry and cattle across the country, it is, in reality, a deeply faulty system. A lot of farmers don’t report illnesses to their veterinarian or state health officials, citing distrust in the government or because they think the epidemic is a hoax. Other farmers do not allow veterinarians to test their flocks or herds for the virus.
If bird flu is detected on a farm or in a live bird market, the USDA mobilizes funding and personnel to those areas to cull — in particularly gruesome ways, such as spraying birds with a water-based foam to suffocate them or closing barn vents and causing birds to die of heat stroke — and dispose of infected animals to prevent further spread. Cows are spared this horrific end because they don’t get so severely sick from bird flu and are too expensive to kill en masse.
J. David Ake/Getty Images
While the USDA works closely with the agricultural sector, the FDA is more consumer-facing, ensuring food products are safe. The FDA monitors egg-laying chickens and those slaughtered for meat for signs of infection. Commercial eggs are tested for H5N1 before they are transported to grocery stores and animals are inspected before and after slaughter for any signs of disease. (We’ll get to how effective this process is in the next section.)
Since the beginning of the outbreak, the FDA has also led a number of studies to test dairy products for H5N1 and to determine how to make contaminated dairy products safe for consumption. The administration also funds academic researchers to test methods for killing the virus in dairy products and even to experiment with gene-edited chickens that are immune to H5N1.
The CDC, meanwhile, monitors H5N1 infections among humans, tracks people who were exposed to infected animals, and investigates each reported case to determine how the person was infected and if any close contacts of the infected person may also be at risk of contracting bird flu.
State health departments are required to report cases to the CDC; doctors and physicians are, in turn, mandated to report H5N1 cases to state health departments. The CDC also gathers and analyzes data from emergency departments around the US to understand if there might be an uptick in H5N1 cases. But, as we have seen with Covid and Mpox, this system does not always function perfectly, or at times even well, because of reporting lags and a lack of infrastructure or human resources. The CDC also runs a wastewater surveillance system and regularly tests wastewater samples from hundreds of collection sites for H5N1.
Although the FDA, USDA, and CDC might seem to have all the legislation, policies, monitoring, and surveillance programs in place, federal government agencies seem to have resigned themselves to largely sitting back and watching this epidemic unfold. Veterinarians and public health experts have criticized the USDA for prioritizing industry profits and exports instead of rolling out a vaccination program that may have prevented bird flu from spilling over into cows or humans in the first place. The USDA has also failed to take obvious measures such as shutting down cross-state transportation of cattle, which has led to hundreds of infected herds in multiple states.
Other efforts — such as the USDA’s national milk testing program — have been too little, too late and still do not require mandatory participation from every US state where bird flu has been reported. And while most of the failure to contain bird flu lies with the FDA and USDA, the CDC has not pushed to expedite research and development for a bird flu vaccine in humans, which might be needed if the disease becomes more widespread and more severe in people, especially farm workers in close contact with infected animals.
It’s currently unclear what new policies the Trump administration might usher in to combat bird flu in humans or animals. President Donald Trump has vowed to cut federal funding which may impact how the various federal agencies operate. Concerningly, on Tuesday, the Trump administration ordered staff at agencies including the CDC and FDA to pause external communications, including social media and web posts, to the public.
When will egg prices go down?
The USDA forecasts that egg prices will continue to rise through the first few months of 2025 before dropping to about half the peak price, according to the agency’s January forecasts. However, new or expanding outbreaks in the US could disrupt this.
Can you contract bird flu from contaminated eggs, milk, and other meat and dairy products?
In short, it’s very unlikely that the average American will contract bird flu from consuming milk, eggs, cheese, meat, or other animal products. Although the FDA found last year that about 20 percent of milk, cheese, and other dairy products contained genetic material from the bird flu virus, researchers at the agency also confirmed that pasteurization — the process of briefly heating milk — kills the virus. Fortunately, 99 percent of the country’s milk supply comes from farms that participate in the agency’s milk safety program which mandates that milk is pasteurized. This means that buying milk or cheese from a grocery store in the US is a safe bet. To be sure, check the label to make sure it contains the word “pasteurized.”
What might be riskier is buying milk from noncommercial farms, like a vendor at your local farmers market or your neighbor down the street who sells milk or cheese out of their house. If that vendor or neighbor pasteurizes their milk, then you’re probably good to go.
Justin Sullivan/Getty Images
There is also a growing trend of consuming raw milk, or milk that has not been pasteurized. Some social media influencers claim that raw milk is healthier than pasteurized milk. A handful of scientific studies have even reported a link between consuming “farm” milk, which sometimes includes raw milk, with a lower risk of developing allergies and asthma. The FDA has, however, debunked many of the health claims associated with raw milk and further warns that drinking raw milk may expose people to H5N1 and a host of other disease-causing pathogens. (Between 1998 and 2018, consuming raw milk caused more than 2,600 illnesses, more than 200 of which required hospitalization.)
So, your best bet is to avoid drinking raw milk and stick to the pasteurized stuff.
Eggs and chicken are also safe to consume. Avian influenza causes such severe disease in chickens and other egg-producing poultry that infected animals are most likely too sick to even produce eggs. But even if sick chickens were producing eggs or were slaughtered for their meat, all commercial poultry flocks in the US are monitored for signs of infection. All eggs are tested for H5N1 before they are transported to grocery stores and animals are inspected before and after slaughter for any signs of disease.
But such inspections aren’t 100 percent foolproof. While the FDA also requires eggs to be tested for other pathogens such as salmonella before they leave the farm, outbreaks of those diseases still occur from time to time. (A salmonella outbreak in 2024, for instance, spanned 12 states and landed 34 people in the hospital.) This may be, in part, because not every single egg is tested for salmonella. Egg producers are required only to test a representative sample of eggs from each batch. Eggs can also be contaminated during packing or transportation from the farm to the grocery store.
The good news is that cooking eggs and meat to recommended temperatures and using proper precautions when handling eggs or meat (like washing your hands after handling them) would also kill the bird flu virus.
What’s the deal with bird flu vaccines?
Currently, there are no bird flu vaccines available for humans or poultry or cows. The CDC has developed a few vaccine candidates for humans that the agency says could be used to develop a vaccine. Additional data regarding the vaccine’s effectiveness has not been released. According to the CDC, the annual flu shot offers no protection against bird flu, but it is unclear if or how the agency actually tested this.
While it is critical for the US government to continue funding vaccine research and development in case a deadlier pandemic emerges, the CDC says there is not an immediate need for widespread vaccination efforts. There have been fewer than 100 documented human infections in the US in the past year. This is likely an undercount given that farm workers are most likely to be infected and may be less likely to seek medical treatment. But more importantly, health officials have documented only three severe bird flu cases, and only one case resulted in death. Globally, there have been nearly 1,000 H5N1 infections among humans between 2003 and 2024, and about half of those people died.
Any threat from the virus now has to be weighed against potential side effects of vaccines, such as Guillain-Barré Syndrome, a condition triggered by an infection that causes the immune system to attack nerves. Given that the current H5N1 strain is causing mostly mild disease, then, at least as of right now, most people would not need to get vaccinated against bird flu even if a vaccine was available.
However, this could change rapidly. Any day, the H5N1 virus might mutate to spread from person to person or to cause more severe illness, in which case vaccination might become an important tool.
Another approach for vaccination might be to only vaccinate farm workers and other populations who are exposed to infected birds or cattle, and therefore at a higher risk of developing bird flu. Last year, Finland adopted this approach and started offering bird flu vaccines to farm workers.
Perhaps the better question to ask here is why we aren’t vaccinating birds or cows against bird flu. I posed that question to infectious disease experts and an economist at the Food and Agriculture Organization last May. I learned that, in short, vaccinating poultry against bird flu would impact trade and would require US trade agreements with foreign countries to be rewritten. The veterinarians I interviewed were particularly frustrated with this reasoning.
“I’m a poultry veterinarian, and as a veterinarian, I don’t like the idea that you tell me to go fight the biggest fight of my career and you say, here’s your gun; first, let’s unload it. Now, go,” Carol Cardona, a professor at the University of Minnesota’s College of Veterinary Medicine, told me last year.
Last week, the USDA said it was beginning to stockpile bird flu vaccines for use in poultry but still hasn’t pushed for actual vaccination efforts. The USDA has a history of this. During the 2014–2015 bird flu outbreak, the US government stockpiled almost 5 million doses of a vaccine for poultry but never used them. But because bird flu, like the seasonal flu, is a rapidly mutating virus, those vaccines are now useless.
Will bird flu cause the next pandemic?
In the US, bird flu has been circulating among birds for nearly three years now and has been sporadically spreading from birds to humans for about a year. It hasn’t caused a widespread pandemic among humans yet. That might indicate that the potential for a future pandemic is low, but, in truth, scientists and public health officials really aren’t great at predicting or even understanding why certain viruses suddenly escalate into uncontrollable worldwide outbreaks.
The key ingredient this epidemic needs to become a widespread pandemic among people is human-to-human transmission. So far, there have been no documented instances of this. For this reason, the CDC says that bird flu presents a low risk to the general public. Farm workers, hunters, and other people who come into contact with wild birds, poultry, and cows are at a higher risk of contracting H5N1.
However, while the risk to most people might be low now, the longer the epidemic in poultry continues and the more opportunities the virus has to adapt to spread amongst humans, the more likely the risk for a pandemic becomes.
