Science

Just one mutation can make H5N1 bird flu a threat to humans, California researchers say

Published

1 year ago

December 5, 2024

Just one mutation can make H5N1 bird flu a threat to humans, California researchers say

California researchers say the world may be just one genetic tweak away from human-to-human transmission of the H5N1 bird flu virus — a worrisome mutation that could open the door to widespread human infections and possibly even a pandemic, according to some experts.

In a study published Thursday in the journal Science, Scripps Research Institute biologists determined that a single mutation of the hemagglutinin protein — the “H” in H5N1 — could transform a virus that has so far sickened or killed mostly birds and cows into a pathogen that targets cells in human beings.

The finding comes amid a growing number of H5N1 outbreaks among California dairy cows, as well as a state-ordered recall of raw milk products. Since the virus began infecting the nation’s dairy stock in March, infectious disease experts have warned that unprotected contact between dairy workers and infected cows could enable the virus to evolve in a manner that threatens humans.

Now, Scripps researchers suggest the path for such a genetic change may be much shorter than state and national health officers anticipated.

“This really surprised us,” said study coauthor James Paulson, a biochemist and molecular biologist. This one mutation “satisfies a requirement for transmission,” he said.

Richard Webby, director of the World Health Organization’s Collaborating Center for Studies on the Ecology of Influenza in Animals and Birds, said the study’s finding countered prevailing thought on the virus — specifically, that it would take multiple mutations for the virus to pose a threat to humans.

“This will likely cause a stir,” said Webby, who is also a researcher in the department of infectious diseases at St. Jude Children’s Research Hospital in Memphis, Tenn., and was not involved in the Scripps research.

“I think most of us thought it would probably need more than one change,” Webby said.

Yoshihiro Kawaoka, a virologist at the University of Wisconsin-Madison and the University of Tokyo, called the Scripps teams’ finding a “significant discovery” and said it was “critical because, given the mutation rate of influenza viruses, one in every 10,000 particles of the bovine H5N1 virus could carry this mutation.”

That means the potential emergence of an H5N1 virus “that can recognize human receptors is closer than we may have thought,” he said.

Several months ago, Paulson and coauthor Ian Wilson, a Scripps structural biologist, decided they’d investigate the current H5N1 strain, and see what it would take for it to cause a human pandemic.

Paulson is an expert in researching where and how different influenza viruses bind to cells when they enter a host. Wilson studies the structure of influenza virus proteins.

The scientists began their research by accessing a global influenza database and locating the genetic sequence for A/Texas/37/2024 — the strain of H5N1 bird flu found in a Texas dairy worker.

They then examined the hemagglutinin proteins, or spikes, on the outer surface of the virus, since those enable it to latch onto the cell membrane of its host. Animals such as birds and humans have different docking stations on their cells — known as sialic acid receptors. In order for a flu virus to open a door into a cell and begin replicating, it needs just the right spike, or key.

Although more than 50 humans have been infected by H5N1, many of these cases involve dairy workers who were likely sprayed in the eyes and nose with milk from infected cows. Researchers postulate that repeated exposure of this sort allowed the virus to push into the cells — a brute force entry more than a lock-picking.

Ordinarily, person-to-person transmission of a flu virus “is mainly through the air from droplets from a sneeze or cough, which contains very little virus,” Paulson said. “In this context, the virus needs to be able to recognize human-type receptors to bind to cells in the human airway in amounts sufficient to cause infection.”

In order to figure out what it would take for the virus to gain the right docking equipment to unleash a human pandemic, Paulson, Wilson and their team looked at previous flu outbreaks that had jumped the bird-human divide, including the influenza outbreaks of 1918, 1957, 1968 and 2009 — as well as some earlier research.

They “selected a number of positions” on the hemagglutinin protein “to mutate, one at a time” with amino acids they knew had been implicated in previous pandemics.

Then they attempted to bind these altered “H” proteins with human and bird receptor analogues.

Lo and behold, when they switched a glutamine to a leucine at position 226, it no longer bound to the bird receptors, but instead exclusively to those of humans.

Paulson said it was especially interesting because this mutation had occurred before in earlier strains of H5N1, including one from around 2010 — but “at that time, that single mutation was not sufficient to change receptor specificity. So, the unexpected thing is that virus has changed in subtle ways — evolved, if you will — so that now that single mutation does change the receptor specificity.”

Although the researchers demonstrated that it was possible for the virus to become a threat to humans with just one genetic change, that does not mean nature will follow that specific path. A multitude of factors can influence the evolution of an organism, and they are not easily predicted. This may be why the virus has not yet gained the ability to widely infect humans, some say.

“Despite more than 50 human infections with bovine H5N1, we have not seen evidence of this virus adapting to humans on a larger scale,” Kawaoka said. “This suggests that … additional mutations are likely required for the virus to become fully transmissible between humans.”

Paulson acknowledged that the “context of the total biological picture is extremely important.”

He said the research focused on just “one property that is important for the virus to be successful when adapting to a new host,” but there are others that may also be important.

For instance, H5N1 in the past was known to cause severe respiratory disease. But recently, it’s mostly been associated with conjunctivitis and only occasionally with mild, upper respiratory disease in people.

“Why is that? I don’t think anybody knows,” Paulson said.

What is known is that the virus is moving swiftly through a variety of species around the globe — with ample opportunity to mutate and adapt.

As of Thursday, the Centers for Disease Control and Prevention had confirmed H5N1 infections in 58 people: 35 as a result of working with infected dairy cows, 21 from infected poultry, and in two cases, the source is unknown.

In addition, 707 dairy herds across 15 states have also been infected. And in just the last 30 days, 23 commercial poultry farms in California have come down with the virus — affecting more than 5.6 million birds.

Science

AI windfall helps California narrow projected $3-billion budget deficit

Published

19 hours ago

January 10, 2026

Press Room

AI windfall helps California narrow projected -billion budget deficit

p]:text-cms-story-body-color-text clearfix”>

SACRAMENTO — California and its state-funded programs are heading into a period of volatile fiscal uncertainty, driven largely by events in Washington and on Wall Street.

Gov. Gavin Newsom’s budget chief warned Friday that surging revenues tied to the artificial intelligence boom are being offset by rising costs and federal funding cuts. The result: a projected $3-billion state deficit for the next fiscal year despite no major new spending initiatives.

The Newsom administration on Friday released its proposed $348.9-billion budget for the fiscal year that begins July 1, formally launching negotiations with the Legislature over spending priorities and policy goals.

“This budget reflects both confidence and caution,” Newsom said in a statement. “California’s economy is strong, revenues are outperforming expectations, and our fiscal position is stable because of years of prudent fiscal management — but we remain disciplined and focused on sustaining progress, not overextending it.”

Newsom’s proposed budget did not include funding to backfill the massive cuts to Medicaid and other public assistance programs by President Trump and the Republican-led Congress, changes expected to lead to millions of low-income Californians losing healthcare coverage and other benefits.

“If the state doesn’t step up, communities across California will crumble,” California State Assn. of Counties Chief Executive Graham Knaus said in a statement.

The governor is expected to revise the plan in May using updated revenue projections after the income tax filing deadline, with lawmakers required to approve a final budget by June 15.

Newsom did not attend the budget presentation Friday, which was out of the ordinary, instead opting to have California Director of Finance Joe Stephenshaw field questions about the governor’s spending plan.

“Without having significant increases of spending, there also are no significant reductions or cuts to programs in the budget,” Stephenshaw said, noting that the proposal is a work in progress.

California has an unusually volatile revenue system — one that relies heavily on personal income taxes from high-earning residents whose capital gains rise and fall sharply with the stock market.

Entering state budget negotiations, many expected to see significant belt tightening after the nonpartisan Legislative Analyst’s Office warned in November that California faces a nearly $18-billion budget shortfall. The governor’s office and Department of Finance do not always agree, or use the LAO’s estimates.

On Friday, the Newsom administration said it is projecting a much smaller deficit — about $3 billion — after assuming higher revenues over the next three fiscal years than were forecast last year. The gap between the governor’s estimate and the LAO’s projection largely reflects differing assumptions about risk: The LAO factored in the possibility of a major stock market downturn.

“We do not do that,” Stephenshaw said.

Among the key areas in the budget:

Science

California confirms first measles case for 2026 in San Mateo County as vaccination debates continue

Published

1 day ago

January 10, 2026

Press Room

California confirms first measles case for 2026 in San Mateo County as vaccination debates continue

Barely more than a week into the new year, the California Department of Public Health confirmed its first measles case of 2026.

The diagnosis came from San Mateo County, where an unvaccinated adult likely contracted the virus from recent international travel, according to Preston Merchant, a San Mateo County Health spokesperson.

Measles is one of the most infectious viruses in the world, and can remain in the air for two hours after an infected person leaves, according to the CDPH. Although the U.S. announced it had eliminated measles in 2000, meaning there had been no reported infections of the disease in 12 months, measles have since returned.

Last year, the U.S. reported about 2,000 cases, the highest reported count since 1992, according to CDC data.

“Right now, our best strategy to avoid spread is contact tracing, so reaching out to everybody that came in contact with this person,” Merchant said. “So far, they have no reported symptoms. We’re assuming that this is the first [California] measles case of the year.”

San Mateo County also reported an unvaccinated child’s death from influenza this week.

Across the country, measles outbreaks are spreading. Today, the South Carolina State Department of Public Health confirmed the state’s outbreak had reached 310 cases. The number has been steadily rising since an initial infection in July spread across the state and is now reported to be connected with infections in North Carolina and Washington.

Similarly to San Mateo’s case, the first reported infection in South Carolina came from an unvaccinated person who was exposed to measles while traveling internationally.

At the border of Utah and Arizona, a separate measles outbreak has reached 390 cases, stemming from schools and pediatric centers, according to the Utah Department of Health and Human Services.

Canada, another long-standing “measles-free” nation, lost ground in its battle with measles in November. The Public Health Agency of Canada announced that the nation is battling a “large, multi-jurisdictional” measles outbreak that began in October 2024.

If American measles cases follow last year’s pattern, the United States is facing losing its measles elimination status next.

For a country to lose measles-free status, reported outbreaks must be of the same locally spread strain, as was the case in Canada. As many cases in the United States were initially connected to international travel, the U.S. has been able to hold on to the status. However, as outbreaks with American-origin cases continue, this pattern could lead the Pan American Health Organization to change the country’s status.

In the first year of the Trump administration, officials led by Health Secretary Robert F. Kennedy Jr. have promoted lowering vaccine mandates and reducing funding for health research.

In December, Trump’s presidential memorandum led to this week’s reduced recommended childhood vaccines; in June, Kennedy fired an entire CDC vaccine advisory committee, replacing members with multiple vaccine skeptics.

Experts are concerned that recent debates over vaccine mandates in the White House will shake the public’s confidence in the effectiveness of vaccines.

“Viruses and bacteria that were under control are being set free on our most vulnerable,” Dr. James Alwine, a virologist and member of the nonprofit advocacy group Defend Public Health, said to The Times.

According to the CDPH, the measles vaccine provides 97% protection against measles in two doses.

Common symptoms of measles include cough, runny nose, pink eye and rash. The virus is spread through breathing, coughing or talking, according to the CDPH.

Measles often leads to hospitalization and, for some, can be fatal.

Science

Trump administration declares ‘war on sugar’ in overhaul of food guidelines

Published

4 days ago

January 7, 2026

Press Room

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.