Science
New genetic research points to Wuhan animal market as origin of COVID pandemic, study says
A new analysis of genetic material gathered from a live-animal market in Wuhan in the early weeks of the COVID-19 pandemic strengthens the case that the outbreak originated there when the coronavirus jumped from infected animals to humans, scientists said.
The findings, reported the journal Cell, do not identify any specific infected animal that brought the SARS-CoV-2 virus to a Chinese city inhabited by more than 11 million people. Nor do they definitively prove that the Huanan Seafood Wholesale Market was Ground Zero for a pandemic that has resulted in more than 7 million deaths.
But the genetic evidence shows the market met the conditions necessary to spark an outbreak and makes it increasingly difficult to explain how the coronavirus could have emerged from a laboratory, a farm or even from another of the city’s four live-animal markets, the study authors said.
“It’s like if a gorilla virus emerged in San Diego and first hit people who worked at the San Diego Zoo and lived nearby, then spread later more widely,” said Michael Worobey, an evolutionary biologist at the University of Arizona who worked on the study. “It would not be difficult to reason that it very likely came from the gorillas at the zoo.”
The root cause of the pandemic has been hotly debated since its early days. Wuhan is home to a government laboratory where scientists study coronaviruses similar to SARS-CoV-2, a fact that prompted politicians, national security experts, late-night talk show hosts and many scientists — including Worobey — to question whether the virus had leaked from the lab.
Compelling though the argument may be, hard evidence to support the leak hypothesis has been lacking. Meanwhile, more information has come to light that has persuaded scientists with expertise in relevant fields that the virus that causes COVID-19 originated in animals, just like the viruses that cause SARS, MERS and influenza.
The new results continue that trend, said Dr. Dominic Dwyer, a member of the international task force that investigated the pandemic’s origins for the World Health Organization.
“You put all of these origin hypotheses on the table, and then some of them become stronger as you get evidence,” said Dwyer, a medical virologist at the University of Sydney and Westmead Hospital in Australia who wasn’t involved in the latest work. “This paper has more evidence that supports the animal origin through the Huanan market.”
The analysis published Thursday was based on genetic data gleaned from hundreds of samples gathered in and around the Huanan market collected by researchers from the Chinese Center for Disease Control and Prevention soon after the market was shut down on Jan. 1, 2020. The Chinese team detected the coronavirus in 74 of the environmental samples they tested, according to their report last year in the journal Nature.
Worobey and his colleagues dug deeper into that data. Using two distinct gene-sequencing techniques, they looked for pieces of SARS-CoV-2 as well as for DNA from animals and people.
Then they plotted what they found on a map of the sprawling market, allowing the team to reconstruct how a few initial infections could have ballooned into a global health emergency.
Among 585 samples gathered in early January 2020, the ones that contained the coronavirus were clustered in the southwestern section of the market. That happened to be the area where wild animals were held in cages for sale.
“The market covers a couple of acres, and this comes down to one corner of the market, and to a couple of stalls,” Dwyer said. “That fits with an animal origin. If it was coming from people wandering around the market, you’d find it everywhere.”
One market stall “stood out,” the study authors wrote. It had evidence of SARS-CoV-2 in multiple places: on at least one cart, on an iron container, on the ground, and on a machine used to remove hair and feathers. The researchers dubbed it “wildlife stall A.”
Another 60 samples were taken from the market’s drainage system at the end of January 2020. The researchers found genetic evidence of the coronavirus in four of them, including one in front of wildlife stall A.
That drain was still testing positive for SARS-CoV-2 in mid-February. So were two drains downstream from it that could have been contaminated by runoff from wildlife stall A, the researchers wrote.
The samples from the stall that contained the coronavirus also contained DNA from a variety of animals, including dogs, rabbits, hoary bamboo rats, Malayan porcupines and masked palm civets. The most abundant DNA was from raccoon dogs, and some was detected in a nearby garbage cart that also tested positive for the virus.
The closest-known relatives to SARS-CoV-2 that exist in the wild are coronaviruses that circulate in horseshoe bats in southern China, Laos and Vietnam and in pangolins from southern China. But no DNA from bats or pangolins turned up in any of the Huanan market samples.
Raccoon dogs, masked palm civets, hoary bamboo rats and Malayan porcupines have transmitted bat coronaviruses before, the study authors noted. Could they have done so in Wuhan, they wondered?
Security guards stand in front of the closed Huanan Seafood Wholesale Market in Wuhan on Jan. 11, 2020.
(Noel Celis / AFP via Getty Images)
It is unclear whether bamboo rats or Malayan porcupines can be infected with SARS-CoV-2, the study authors wrote. There is no hard evidence that masked palm civets can catch the virus, but cell lines from the animals were susceptible in laboratory experiments.
Raccoon dogs, on the other hand, are known to catch and transmit SARS-CoV-2. And they were the most abundant animal in wildlife stall A.
The researchers dug into the raccoon dog DNA to see if they could have come from southern China, where they might have crossed paths with bats. They couldn’t tell, but they were able to rule out a connection to raccoon dogs that lived on fur farms in northern China.
Worobey and his colleagues also studied non-SARS-CoV-2 animal viruses that were detected in wildlife stalls to see if they offered clues about where the infected animals had come from.
A kobuvirus that infected civets in the Huanan market was closely related to a virus detected in animals sold in Sichuan and Guangxi provinces, which are closer to the territory of horseshoe bats and pangolins. And a betacoronavirus that infected bamboo rats had a close relative on a bamboo rat farm in Guangxi, one of two southern provinces where market vendors were known to have sourced the animals.
“These findings suggest some movement of infected animals from southern China to Wuhan, a trade conduit that could have also led to the emergence of SARS-CoV-2,” the study authors wrote.
Nailing this down will require more sleuthing, including field work to collect samples from animals in China, said Florence Débarre, an evolutionary biologist at the French National Centre for Scientific Research in Paris and the study’s senior author. Worobey said he plans to continue this line of inquiry.
Dwyer praised the effort to determine where the animals in the market had come from — and by extension, how the virus could have gotten to the market.
A second line of evidence also supports the hypothesis that the pandemic had a so-called zoonotic origin, scientists said.
Among the samples collected at the Huanan market on Jan. 1, 2020, the researchers were able to identify four nearly complete SARS-CoV-2 genomes. One of them was from so-called lineage A, and the other three were from the closely related lineage B.
The researchers weren’t able to tell whether those viruses were shed by animals or people, but the lineage A sample came from a stall where a worker sought medical attention in mid-December 2019. Although that was weeks before COVID-19 had been recognized as a disease, a report from the World Health Organization later described the worker as a suspected early patient.
Confirming the presence of both lineages in the market allowed the team to compare their genomes and work backward to figure out when the two strains diverged, and what their most recent common ancestor looked like. They came up with six candidates, some of them more plausible than others.
There was a 99% probability that one of the four most likely candidates was correct, and those four all had something important in common: They were “equivalent or identical” to the most recent common ancestor for the pandemic as a whole, said study leader Alexander Crits-Christoph, an independent computational microbiologist.
That’s what they would expect to find if the outbreak began at the Huanan market, the study authors said. In that scenario, an animal or animals infected with the virus arrived at the market in November or early December. The virus then spread among animals held in close quarters indoors, as well as to their human handlers. Those conditions would have given the virus the multiple chances it needed to establish itself in people and begin spreading among its new hosts in a densely populated city.
On the other hand, it’s getting more difficult to fit all of this evidence into a coherent story that has the coronavirus entering China via imported frozen food (as the Chinese government has claimed) or escaping from a virology lab with lax biosecurity protocols (as some members of the U.S. intelligence community have proposed), Dwyer said.
“We’ve had nothing added to support the lab leak or the frozen food theories,” he said. “It just continues to strengthen the animal and market hypothesis.”
Considering that the pandemic began in a city with a virology lab where scientists study coronaviruses, it makes sense to ask whether that’s more than a coincidence and to wonder whether incriminating evidence is being covered up, DéBarre said.
“Many of us were extremely open to this idea,” she said. “But then data have accumulated, and they all go in the same direction — they all point to the market.”
“In science you very rarely have final answers,” she added. “You say, ‘Given all the data we have, this looks like the most likely interpretation.’”
Science
Trump administration declares ‘war on sugar’ in overhaul of food guidelines
The Trump administration announced a major overhaul of American nutrition guidelines Wednesday, replacing the old, carbohydrate-heavy food pyramid with one that prioritizes protein, healthy fats and whole grains.
“Our government declares war on added sugar,” Health and Human Services Secretary Robert F. Kennedy Jr. said in a White House press conference announcing the changes. “We are ending the war on saturated fats.”
“If a foreign adversary sought to destroy the health of our children, to cripple our economy, to weaken our national security, there would be no better strategy than to addict us to ultra-processed foods,” Kennedy said.
Improving U.S. eating habits and the availability of nutritious foods is an issue with broad bipartisan support, and has been a long-standing goal of Kennedy’s Make America Healthy Again movement.
During the press conference, he acknowledged both the American Medical Association and the American Assn. of Pediatrics for partnering on the new guidelines — two organizations that earlier this week condemned the administration’s decision to slash the number of diseases that U.S. children are vaccinated against.
“The American Medical Association applauds the administration’s new Dietary Guidelines for spotlighting the highly processed foods, sugar-sweetened beverages, and excess sodium that fuel heart disease, diabetes, obesity, and other chronic illnesses,” AMA president Bobby Mukkamala said in a statement.
Science
Contributor: With high deductibles, even the insured are functionally uninsured
I recently saw a patient complaining of shortness of breath and a persistent cough. Worried he was developing pneumonia, I ordered a chest X-ray — a standard diagnostic tool. He refused. He hadn’t met his $3,000 deductible yet, and so his insurance would have required him to pay much or all of the cost for that scan. He assured me he would call if he got worse.
For him, the X-ray wasn’t a medical necessity, but it would have been a financial shock he couldn’t absorb. He chose to gamble on a cough, and five days later, he lost — ending up in the ICU with bilateral pneumonia. He survived, but the cost of his “savings” was a nearly fatal hospital stay and a bill that will quite likely bankrupt him. He is lucky he won’t be one of the 55,000 Americans to die from pneumonia each year.
As a physician associate in primary care, I serve as a frontline witness to this failure of the American approach to insurance. Medical professionals are taught that the barrier to health is biology: bacteria, viruses, genetics. But increasingly, the barrier is a policy framework that pressures insured Americans to gamble with their lives. High-deductible health plans seem affordable because their monthly premiums are lower than other plans’, but they create perverse incentives by discouraging patients from seeking and accepting diagnostics and treatments — sometimes turning minor, treatable issues into expensive, life-threatening emergencies. My patient’s gamble with his lungs is a microcosm of the much larger gamble we are taking with the American public.
The economic theory underpinning these high deductibles is known as “skin in the game.” The idea is that if patients are responsible for the first few thousand dollars of their care, they will become savvy consumers, shopping around for the best value and driving down healthcare costs.
But this logic collapses in the exam room. Healthcare is not a consumer good like a television or a used car. My patient was not in a position to “shop around” for a cheaper X-ray, nor was he qualified to determine if his cough was benign or deadly. The “skin in the game” theory assumes a level of medical literacy and market transparency that simply doesn’t exist in a moment of crisis. You can compare the specs of two SUVs; you cannot “shop around” for a life-saving diagnostic while gasping for air.
A 2025 poll from the Kaiser Family Foundation points to this reality, finding that up to 38% of insured American adults say they skipped or postponed necessary healthcare or medications in the past 12 months because of cost. In the same poll, 42% of those who skipped care admitted their health problem worsened as a result.
This self-inflicted public health crisis is set to deteriorate further. The Congressional Budget Office estimates roughly 15 million people will lose health coverage and become uninsured by 2034 because of Medicaid and Affordable Care Act marketplace cuts. That is without mentioning the millions more who will see their monthly premiums more than double if premium tax credits are allowed to expire. If that happens, not only will millions become uninsured but also millions more will downgrade to “bronze” plans with huge deductibles just to keep their premiums affordable. We are about to flood the system with “insured but functionally uninsured” patients.
I see the human cost of this “functional uninsurance” every week. These are patients who technically have coverage but are terrified to use it because their deductibles are so large they may exceed the individuals’ available cash or credit — or even their net worth. This creates a dangerous paradox: Americans are paying hundreds of dollars a month for a card in their wallet they cannot afford to use. They skip the annual physical, ignore the suspicious mole and ration their insulin — all while technically insured. By the time they arrive at my clinic, their disease has often progressed to a catastrophic event, from what could have been a cheap fix.
Federal spending on healthcare should not be considered charity; it is an investment in our collective future. We cannot expect our children to reach their full potential or our workforce to remain productive if basic healthcare needs are treated as a luxury. Inaction by Congress and the current administration to solve this crisis is legislative malpractice.
In medicine, we are trained to treat the underlying disease, not just the symptoms. The skipped visits and ignored prescriptions are merely symptoms; the disease is a policy framework that views healthcare as a commodity rather than a fundamental necessity. If we allow these cuts to proceed, we are ensuring that the American workforce becomes sicker, our hospitals more overwhelmed and our economy less resilient. We are walking willingly into a public health crisis that is entirely preventable.
Joseph Pollino is a primary care physician associate in Nevada.
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Ideas expressed in the piece
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High-deductible health plans create a barrier to necessary medical care, with patients avoiding diagnostics and treatments due to out-of-pocket cost concerns[1]. Research shows that 38% of insured American adults skipped or postponed necessary healthcare or medications in the past 12 months because of cost, with 42% reporting their health worsened as a result[1].
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The economic theory of “skin in the game”—which assumes patients will shop around for better healthcare values if they have financial responsibility—fails in medical practice because patients lack the medical literacy to make informed decisions in moments of crisis and cannot realistically compare pricing for emergency or diagnostic services[1].
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Rising deductibles are pushing enrollees toward bronze plans with deductibles averaging $7,476 in 2026, up from the average silver plan deductible of $5,304[1][4]. In California’s Covered California program, bronze plan enrollment has surged to more than one-third of new enrollees in 2026, compared to typically one in five[1].
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Expiring federal premium tax credits will more than double out-of-pocket premiums for ACA marketplace enrollees in 2026, creating an expected 75% increase in average out-of-pocket premium payments[5]. This will force millions to either drop coverage or downgrade to bronze plans with massive deductibles, creating a population of “insured but functionally uninsured” people[1].
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High-deductible plans pose particular dangers for patients with chronic conditions, with studies showing adults with diabetes involuntarily switched to high-deductible plans face 11% higher risk of hospitalization for heart attacks, 15% higher risk for strokes, and more than double the likelihood of blindness or end-stage kidney disease[4].
Different views on the topic
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Expanding access to health savings accounts paired with bronze and catastrophic plans offers tax advantages that allow higher-income individuals to set aside tax-deductible contributions for qualified medical expenses, potentially offsetting higher out-of-pocket costs through strategic planning[3].
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Employers and insurers emphasize that offering multiple plan options with varying deductibles and premiums enables employees to select plans matching their individual needs and healthcare usage patterns, allowing those who rarely use healthcare to save money through lower premiums[2]. Large employers increasingly offer three or more medical plan choices, with the expectation that employees choosing the right plan can unlock savings[2].
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The expansion of catastrophic plans with streamlined enrollment processes and automatic display on HealthCare.gov is intended to make affordable coverage more accessible for certain income groups, particularly those above 400% of federal poverty level who lose subsidies[3].
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Rising healthcare costs, including specialty drugs and new high-cost cell and gene therapies, are significant drivers requiring premium increases regardless of plan design[5]. Some insurers are managing affordability by discontinuing costly coverage—such as GLP-1 weight-loss medications—to reduce premium rate increases for broader plan members[5].
Science
Trump administration slashes number of diseases U.S. children will be regularly vaccinated against
The U.S. Department of Health and Human Services announced sweeping changes to the pediatric vaccine schedule on Monday, sharply cutting the number of diseases U.S. children will be regularly immunized against.
Under the new guidelines, the U.S. still recommends that all children be vaccinated against measles, mumps, rubella, polio, pertussis, tetanus, diphtheria, Haemophilus influenzae type B (Hib), pneumococcal disease, human papillomavirus (HPV) and varicella, better known as chickenpox.
Vaccines for all other diseases will now fall into one of two categories: recommended only for specific high-risk groups, or available through “shared clinical decision-making” — the administration’s preferred term for “optional.”
These include immunizations for hepatitis A and B, rotavirus, respiratory syncytial virus (RSV), bacterial meningitis, influenza and COVID-19. All these shots were previously recommended for all children.
Insurance companies will still be required to fully cover all childhood vaccines on the CDC schedule, including those now designated as optional, according to the Department of Health and Human Services.
Health Secretary Robert F. Kennedy Jr., a longtime vaccine critic, said in a statement that the new schedule “protects children, respects families, and rebuilds trust in public health.”
But pediatricians and public health officials widely condemned the shift, saying that it would lead to more uncertainty for patients and a resurgence of diseases that had been under control.
“The decision to weaken the childhood immunization schedule is misguided and dangerous,” said Dr. René Bravo, a pediatrician and president of the California Medical Assn. “Today’s decision undermines decades of evidence-based public health policy and sends a deeply confusing message to families at a time when vaccine confidence is already under strain.”
The American Academy of Pediatrics condemned the changes as “dangerous and unnecessary,” and said that it will continue to publish its own schedule of recommended immunizations. In September, California, Oregon, Washington and Hawaii announced that those four states would follow an independent immunization schedule based on recommendations from the AAP and other medical groups.
The federal changes have been anticipated since December, when President Trump signed a presidential memorandum directing the health department to update the pediatric vaccine schedule “to align with such scientific evidence and best practices from peer, developed countries.”
The new U.S. vaccination guidelines are much closer to those of Denmark, which routinely vaccinates its children against only 10 diseases.
As doctors and public health experts have pointed out, Denmark also has a robust system of government-funded universal healthcare, a smaller and more homogenous population, and a different disease burden.
“The vaccines that are recommended in any particular country reflect the diseases that are prevalent in that country,” said Dr. Kelly Gebo, dean of the Milken Institute School of Public Health at George Washington University. “Just because one country has a vaccine schedule that is perfectly reasonable for that country, it may not be at all reasonable” elsewhere.
Almost every pregnant woman in Denmark is screened for hepatitis B, for example. In the U.S., less than 85% of pregnant women are screened for the disease.
Instead, the U.S. has relied on universal vaccination to protect children whose mothers don’t receive adequate care during pregnancy. Hepatitis B has been nearly eliminated in the U.S. since the vaccine was introduced in 1991. Last month, a panel of Kennedy appointees voted to drop the CDC’s decades-old recommendation that all newborns be vaccinated against the disease at birth.
“Viruses and bacteria that were under control are being set free on our most vulnerable,” said Dr. James Alwine, a virologist and member of the nonprofit advocacy group Defend Public Health. “It may take one or two years for the tragic consequences to become clear, but this is like asking farmers in North Dakota to grow pineapples. It won’t work and can’t end well.”
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