When avian influenza first hit dairy cows a year ago, it seemed like it could affect a few isolated herds and disappear as quickly as it appeared. Instead, the virus has infected more than 900 herds and dozens of others, killing one person, and the outbreak shows no signs of abating.
A pandemic is still not inevitable, more than a dozen experts said in interviews. However, a series of developments over the past few weeks indicate that possibility is no longer remote.
Toothless guidelines, inadequate testing and long delays in releasing data – echoes of missteps during the covid-19 pandemic – are squandering opportunities to contain the outbreak, experts said.
In an emblematic example of the confusion, several dairy herds in Idaho infected in the spring showed mild symptoms a second time in late fall, The New York Times has learned. In mid-January, the Department of Agriculture said no new infections had been identified in the Idaho herd since October. However, state officials publicly discussed the milder incident in November.
It’s not surprising that a second infection causes milder symptoms in cattle, experts said, and the news may be welcome to farmers. But reinfection suggests the virus, called H5N1, could circulate on farms indefinitely and create an opportunity to evolve into a more dangerous form – a “high-risk” scenario, according to the University of Pennsylvania’s Evolutionary Biology Society. said the scholar Louise Moncla.
“You could easily end up permanently circulating H5 in dairy herds without symptoms, obscuring quick or easy detection,” Dr. Monka said.
It is impossible to predict whether a virus will evolve the ability to spread between people. But the worry is that if bird flu finds the right combination of genetic mutations, the outbreak could quickly escalate.
“I’m not worried about the leeches from Puck My Bag and Head yet, but there have been more signals in the last four to six weeks that this virus has the ability to cause a pandemic,” Richard said. Ta. Webby, an influenza expert at St. Jude Children’s Research Hospital.
Federal officials have also subtly changed their tone when discussing the outbreak, now emphasizing how quickly the situation can change.
For the general public, he said, H5N1 is a “low risk compared to other risks we face today.” But “100%, that could change,” he said. “This is a dangerous virus.”
Health experts emphasize there are precautions Americans can take. Do not touch sick or dead birds or other animals. If you have clear symptoms, you will be tested. Do not consume raw milk or meat or feed it to pets.
If a larger outbreak erupts, the federal vaccine stockpile holds millions of doses, but the vaccines may first need to be updated for evolving forms of the virus. In either case, authorities must scramble to produce enough for the population.
The CDC recommends treatment with the antiviral Tamiflu, but studies have shown that this drug does little to alleviate the disease.
A concern that underscores concerns among many experts is that, if confirmed, Robert F. Kennedy Jr., who heads the federal health agency, is a vocal critic of the Covid vaccine, saying the bird flu vaccine “appears to be dangerous.” “It looks like it,” he said.
Even if the second Trump administration embraces vaccine developments, it’s unclear how many Americans will roll up their sleeves for a shot, as the first administration did when covid went down. Influenza usually affects children and the elderly, and pandemic influenza can hit young adults hardest. But mistrust brought on during Covid-19 may cause Americans to avoid precautions, at least at first.
evolving threat
Unlike coronaviruses, which wreak havoc upon their sudden arrival, influenza viruses typically start in specific animal species or specific geographic regions.
When H5N1 emerged in East Asia nearly 30 years ago, it was mostly sick birds. Over the next few years, it infected at least 940 people, nearly all of whom had continued contact with infected birds. About half of those people died.
But since January 2022, when the virus was detected in wild aquatic birds in the United States, it has affected more than 136 million commercial, backyard, and wild birds and helped drive up egg prices. It also attacked dozens of mammal species, including wild and domestic cats, raccoons, bears, and sea lions.
For at least a year, H5N1 has been infecting dairy cows, which were not known to be susceptible to this type of influenza. In some cows, it has a permanent effect, reducing milk production and increasing the likelihood of spontaneous abortion.
And in 2024, the virus infected just one American several years before 2022. The source of all these infections is unknown. One person may have passed the virus on to someone else in the household.
Many of these developments are classic steps toward a pandemic, said Dr. James Lawler, director of the Center for Global Health Security at the University of Nebraska. But, he said, “we just shrugged our shoulders as each milestone passed, when they were really supposed to cause acceleration and amplification at the federal, state and local level.”
Infections in dairy herds that first appeared in Texas appeared to be on the decline last summer. But in late August, California announced its first lawsuit. The state’s numbers quickly rose sharply, prompting Gov. Gavin Newsom to declare a public health emergency in December.
“That was kind of a flag for me: ‘OK, this isn’t going away,'” said Dr. Manisha Jutani, commissioner of the Connecticut Department of Public Health. “Over the last few months, it felt like the tempo had increased,” she said.
Several other recent events have raised the level of alarm among experts. In early December, scientists reported that a single mutation helped the virus infect human cells more efficiently in a lab setting.
And late last year, two people, a 13-year-old Canadian girl and a Louisiana resident over 65, became seriously ill. Previously, most people infected with H5N1 did not experience severe symptoms. The Louisiana patient, who had health conditions and cared for sick and dying birds, died in early January.
The girl was placed on life support due to organ failure, but eventually recovered. Scientists still don’t know how she became infected. Her only risk factor was obesity.
Both patients had a new version of the virus that is different from the one in dairy cows and is now spreading to birds. In both individuals, the virus acquired mutations during the course of infection.
“We’re clearly getting a new virus that formed in wild bird reservoirs,” Dr. Monka said. “It’s becoming difficult to handle all the different threats.”
Some experts find it particularly worrying that the virus appears to be in food sources such as raw milk and raw pet food. Domestic cats have died in many states, prompting the recall of at least one brand of pet food and new federal guidelines for pet food quality.
“Raw pet food to me seems like a pretty amazing thing,” said Dr. Jeanne Marazzo, director of the National Institute of Allergy and Infectious Diseases.
Pasteurization, like cooking meat at high temperatures, kills live viruses. Still, neither procedure is perfect, Dr. Marrazzo said.
defective response
Since the outbreak began, federal officials have announced other measures to prevent or prepare for a pandemic. But each is deeply flawed, experts said.
The U.S. Department of Agriculture was slow to begin testing H5N1 vaccines in cattle, leaving stakeholders in limbo. Dr. Marrazzo said the department released genetic information from virus samples but did not say where or where it was collected. Details that help scientists track the evolution of the virus.
It’s also unclear how many herds are reinfected or battling months-long infections. In Idaho, some herds infected in the spring appeared to recover, but showed mild symptoms again in November.
“From the data we have so far, we see no evidence of new infections or reinfection of previously affected herds, but rather a lack of clearance of the original infection,” the USDA said. a spokesperson said in an emailed response. But outside experts said the trajectory of symptoms suggested a second round of the disease.
The USDA’s program to test bulk milk began in December – nearly a year after the outbreak began, but still does not include Idaho. Attracting private companies may help the program move faster.
Ginkgo Bioworks, a company that worked with federal agencies during the Covid pandemic, has already evaluated about half of the country’s commercial milk supply for bacteria, antibiotics and other substances.
Adding H5N1 to the list is easy, so “why not add an assay to this infrastructure that we have?” said Matt McKnight, manager of the company’s biosecurity division.
Earlier this month, the Biden administration announced $366 million in new funding. About a third of that was announced for surveillance, testing and outreach to farm workers.
But farmworkers in some places like the Texas Panhandle still don’t know what avian influenza is, how it spreads or why it’s important to them, according to the National Farm said Bethany Alkauter, director of the Center for Workforce Health’s research and public health program.
As a result, many workers are not using protective equipment, including in milk parlors, where the virus is thought to spread, she said.
Human testing is voluntary and infections are missed. Few farmworkers choose to be tested, fearing immigration officials or their own employers.
“If you’re not looking for it, you won’t find it,” said Dr. Deborah Birx, who served as the White House coronavirus response coordinator under President Trump. “This is not about lockdowns or restrictions on activity. It’s about protecting individual Americans by empowering them with information.”
