How the US is preparing for a potential bird flu pandemic

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This week marks a strange anniversary—it’s five years since most of us first heard about a virus causing a mysterious “pneumonia.” A virus that we later learned could cause a disease called covid-19. A virus that swept the globe and has since been reported to have been responsible for over 7 million deaths—and counting.

I first covered the virus in an article published on January 7, 2020, which had the headline “Doctors scramble to identify mysterious illness emerging in China.” For that article, and many others that followed it, I spoke to people who were experts on viruses, infectious disease, and epidemiology. Frequently, their answers to my questions about the virus, how it might spread, and the risks of a pandemic were the same: “We don’t know.”

We are facing the same uncertainty now with H5N1, the virus commonly known as bird flu. This virus has been decimating bird populations for years, and now a variant is rapidly spreading among dairy cattle in the US. We know it can cause severe disease in animals, and we know it can pass from animals to people who are in close contact with them. As of this Monday this week, we also know that it can cause severe disease in people—a 65-year-old man in Louisiana became the first person in the US to die from an H5N1 infection.

Scientists are increasingly concerned about a potential bird flu pandemic. The question is, given all the enduring uncertainty around the virus, what should we be doing now to prepare for the possibility? Can stockpiled vaccines save us? And, importantly, have we learned any lessons from a covid pandemic that still hasn’t entirely fizzled out?

Part of the challenge here is that it is impossible to predict how H5N1 will evolve.

A variant of the virus caused disease in people in 1997, when there was a small but deadly outbreak in Hong Kong. Eighteen people had confirmed diagnoses, and six of them died. Since then, there have been sporadic cases around the world—but no large outbreaks.

As far as H5N1 is concerned, we’ve been relatively lucky, says Ali Khan, dean of the college of public health at the University of Nebraska. “Influenza presents the greatest infectious-disease pandemic threat to humans, period,” says Khan. The 1918 flu pandemic was caused by a type of influenza virus called H1N1 that appears to have jumped from birds to people. It is thought to have infected a third of the world’s population, and to have been responsible for around 50 million deaths.

Another H1N1 virus was responsible for the 2009 “swine flu” pandemic. That virus hit younger people hardest, as they were less likely to have been exposed to similar variants and thus had much less immunity. It was responsible for somewhere between 151,700 and 575,400 deaths that year.

To cause a pandemic, the H5N1 variants currently circulating in birds and dairy cattle in the US would need to undergo genetic changes that allow them to spread more easily from animals to people, spread more easily between people, and become more deadly in people. Unfortunately, we know from experience that viruses need only a few such changes to become more easily transmissible.

And with each and every infection, the risk that a virus will acquire these dangerous genetic changes increases. Once a virus infects a host, it can evolve and swap chunks of genetic code with any other viruses that might also be infecting that host, whether it’s a bird, a pig, a cow, or a person. “It’s a big gambling game,” says Marion Koopmans, a virologist at the Erasmus University Medical Center in Rotterdam, the Netherlands. “And the gambling is going on at too large a scale for comfort.”

There are ways to improve our odds. For the best chance at preventing another pandemic, we need to get a handle on, and limit, the spread of the virus. Here, the US could have done a better job at limiting the spread in dairy cows, says Khan. “It should have been found a lot earlier,” he says. “There should have been more aggressive measures to prevent transmission, to recognize what disease looks like within our communities, and to protect workers.”

States could also have done better at testing farm workers for infection, says Koopmans. “I’m surprised that I haven’t heard of an effort to eradicate it from cattle,” she adds. “A country like the US should be able to do that.”

The good news is that there are already systems in place for tracking the general spread of flu in people. The World Health Organization’s Global Influenza Surveillance and Response System collects and analyzes samples of viruses collected from countries around the world. It allows the organization to make recommendations about seasonal flu vaccines and also helps scientists track the spread of various flu variants. That’s something we didn’t have for the covid-19 virus when it first took off.

We are also better placed to make vaccines. Some countries, including the US, are already stockpiling vaccines that should be at least somewhat effective against H5N1 (although it is difficult to predict exactly how effective they will be against some future variant). The US Administration for Strategic Preparedness and Response plans to have “up to 10 million doses of prefilled syringes and multidose vials” prepared by the end of March, according to an email from a representative.

The US Department of Health and Human Services has also said it will provide the pharmaceutical company Moderna with $176 million to create mRNA vaccines for pandemic influenza—using the same quick-turnaround vaccine production technology used in the company’s covid-19 vaccines.

Some question whether these vaccines should have already been offered to dairy farm workers in affected parts of the US. Many of these individuals have been exposed to the virus, a good chunk of them appear to have been infected with it, and some of them have become ill. If the decision had been up to Khan, he says, they would have been offered the H5N1 vaccine by now. And we should ensure they are offered seasonal flu vaccines in order to limit the risk that the two flu viruses will mingle inside one person, he adds.

Others worry that 10 million vaccine doses aren’t enough for a country with a population of around 341 million. But health agencies “walk a razor-thin line between having too much vaccine for something and not having enough,” says Khan. If an outbreak never transpires, 340 million doses of vaccine will feel like an enormous waste of resources.

We can’t predict how well these viruses will work, either. Flu viruses mutate all the time, and even seasonal flu vaccines are notoriously unpredictable in their efficacy. “I think we’ve become a little bit spoiled with the covid vaccines,” says Koopmans. “We were really, really lucky [to develop] vaccines with high efficacy.”

One vaccine lesson we should have learned from the covid-19 pandemic is the importance of equitable access to vaccines around the world. Unfortunately, it’s unlikely that we have. “It is doubtful that low-income countries will have early access to [a pandemic influenza] vaccine unless the world takes action,” Nicole Lurie of the Coalition for Epidemic Preparedness Innovations (CEPI) said in a recent interview for Gavi, a public-private alliance for vaccine equity.

And another is the impact of vaccine hesitancy. Making vaccines might not be a problem—but convincing people to take them might be, says Khan. “We have an incoming administration that has lots of vaccine hesitancy,” he points out. “So while we may end up having … vaccines available, it’s not very clear to me if we have the political and social will to actually implement good public health measures.”

This is another outcome that is impossible to predict, and I won’t attempt to do so. But I am hoping that the relevant administrations will step up our defenses. And that this will be enough to prevent another devastating pandemic.

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Bird flu has been circulating in US dairy cows for months. Virologists are worried it could stick around on US farms forever.

As the virus continues to spread, the risk of a pandemic continues to rise. We still don’t really know how the virus is spreading, but we do know that it is turning up in raw milk. (Please don’t drink raw milk.)

mRNA vaccines helped us through the covid-19 pandemic. Now scientists are working on mRNA flu vaccines—including “universal” vaccines that could protect against multiple flu viruses.

The next generation of mRNA vaccines is on the way. These vaccines are “self-amplifying” and essentially tell the body how to make more mRNA. 

Maybe there’s an alternative to dairy farms of the type that are seeing H5N1 in their cattle. Scientists are engineering yeasts and plants with bovine genes so they can produce proteins normally found in milk, which can be used to make spreadable cheeses and ice cream. The cofounder of one company says a factory of bubbling yeast vats could “replace 50,000 to 100,000 cows.”

From around the web

My colleagues and I put together an annual list of what we think are the breakthrough technologies of that year. This year’s list includes long-acting HIV prevention medicines and stem-cell treatments that actually work. Check out the full list here.

Calico, the Google biotech company focused on “tackling aging,” has released results from the trial of a drug to treat amyotrophic lateral sclerosis (ALS). The drug failed. (STAT) 

Around the world, birth rates are falling. The more concerned nations become about this fact, the greater the risk to gender rights, writes Angela Saini. (Wired)

Brooke Eby, a 36-year-old with ALS, is among a niche group of content creators documenting their journeys with terminal illness on social media platforms like TikTok. “I’m glad that I’m sharing my journey. I wish someone had come before me and shared, start to finish …,” she said. “I’m just going to post all this, because maybe it’ll help someone who’s like a year behind me in their progression.” (New York Times)

Do we each have 30 trillion genomes? A growing understanding of genetic mutations that occur in adults is changing the way doctors diagnose and treat disease. (The Atlantic)

Why childhood vaccines are a public health success story

This article first appeared in The Checkup, MIT Technology Review’s weekly biotech newsletter. To receive it in your inbox every Thursday, and read articles like this first, sign up here.

Later today, around 10 minutes after this email lands in your inbox, I’ll be holding my four-year-old daughter tight as she receives her booster dose of the MMR vaccine. This shot should protect her from a trio of nasty infections—infections that can lead to meningitis, blindness, and hearing loss. I feel lucky to be offered it.

This year marks the 50-year anniversary of an ambitious global childhood vaccination program. The Expanded Programme on Immunization was launched by the World Health Organization in 1974 with the goal of getting lifesaving vaccines to all the children on the planet.

Vaccines are estimated to have averted 154 million deaths since the launch of the EPI. That number includes 146 million children under the age of five. Vaccination efforts are estimated to have reduced infant mortality by 40%, and to have contributed an extra 10 billion years of healthy life among the global population.

Childhood vaccination is a success story. But concerns around vaccines endure. Especially, it seems, among the individuals Donald Trump has picked as his choices to lead US health agencies from January. This week, let’s take a look at their claims, and where the evidence really stands on childhood vaccines.

WHO, along with health agencies around the world, recommends a suite of vaccinations for babies and young children. Some, such as the BCG vaccine, which offers some protection against tuberculosis, are recommended from birth. Others, like the vaccines for pertussis, diphtheria, tetanus, and whooping cough, which are often administered in a single shot, are introduced at eight weeks. Other vaccinations and booster doses follow.

The idea is to protect babies as soon as possible, says Kaja Abbas of the London School of Hygiene & Tropical Medicine in the UK and Nagasaki University in Japan.

The full vaccine schedule will depend on what infections pose the greatest risks and will vary by country. In the US, the recommended schedule is determined by the Centers for Disease Control and Prevention, and individual states can opt to set vaccine mandates or allow various exemptions.

Some scientists are concerned about how these rules might change in January, when Donald Trump makes his return to the White House. Trump has already listed his picks for top government officials, including those meant to lead the country’s health agencies. These individuals must be confirmed by the Senate before they can assume these roles, but it appears that Trump intends to surround himself with vaccine skeptics.

For starters, Trump has selected Robert F. Kennedy Jr. as his pick to lead the Department of Health and Human Services. Kennedy, who has long been a prominent anti-vaxxer, has a track record of spreading false information about vaccines.

In 2005, he published an error-laden article in Salon and Rolling Stone linking thimerosal—an antifungal preservative that was previously used in vaccines but phased out in the US by 2001—to neurological disorders in children. (That article was eventually deleted in 2011. “I regret we didn’t move on this more quickly, as evidence continued to emerge debunking the vaccines and autism link,” wrote Joan Walsh, Salon’s editor at large at the time.)

Kennedy hasn’t let up since. In 2015, he made outrageous comments about childhood vaccinations at a screening of a film that linked thimerosal to autism. “They get the shot, that night they have a fever of a hundred and three, they go to sleep, and three months later their brain is gone,” Kennedy said, as reported by the Sacramento Bee. “This is a holocaust, what this is doing to our country.”

Aaron Siri, the lawyer who has been helping Kennedy pick health officials for the upcoming Trump administration, has petitioned the government to pause the distribution of multiple vaccines and to revoke approval of the polio vaccine entirely. And Dave Weldon, Trump’s pick to direct the CDC, also has a history of vaccine skepticism. He has championed the disproven link between thimerosal and autism.

These arguments aren’t new. The MMR vaccine in particular has been subject to debate, controversy, and conspiracy theories for decades. All the way back in 1998, a British doctor, Andrew Wakefield, published a paper suggesting a link between the vaccine and autism in children.

The study has since been debunked—multiple times over—and Wakefield was found to have unethically subjected children to invasive and unnecessary procedures. The paper was retracted 12 years after it was published, and the UK’s General Medical Council found Wakefield guilty of serious professional misconduct. He was struck off the medical register and is no longer allowed to practice medicine in the UK. (He continues to peddle false information, though, and directed the 2016 film Vaxxed, which Weldon appeared in.)

So it’s remarkable that his “study” still seems to be affecting public opinion. A recent Pew Research Center survey suggests that four in 10 US adults worry that “not all vaccines are necessary,” and while most Americans think the benefits outweigh any risks, some are still concerned about side effects. Views among Republicans in particular seem to have shifted over the years. In 2019, 82% supported school-based vaccine requirements. That figure dropped to 70% in 2023.

The problem is that we need more than 70% of children to be vaccinated to reach “herd immunity”—the level needed to protect communities. For a super-contagious infection like measles, 95% of the population needs to be vaccinated, according to WHO. “If [coverage drops to] 80%, we should expect outbreaks,” says Abbas.

And that’s exactly what is happening. In 2023, only 83% of children got their first dose of a measles vaccine through routine health services. Nearly 35 million children are thought to have either partial protection from the disease or none at all. And over the last five years, there have been measles outbreaks in 103 countries.

Polio vaccines—the ones whose approval Siri sought to revoke—have also played a vital role in protecting children, in this case from a devastating infection that can cause paralysis. “People were so afraid of polio in the ‘30s, ‘40s, and ‘50s here in the United States,” says William Moss, an epidemiologist at Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. “When the trial results of [the first] vaccine were announced in the United States, people were dancing in the streets.”

That vaccine was licensed in the US in 1955. By 1994, polio was considered eliminated in North and South America. Today, wild forms of the virus have been eradicated in all but two countries.

But the polio vaccine story is not straightforward. There are two types of polio vaccine: an injected type that includes a “dead” form of the virus, and an oral version that includes “live” virus. This virus can be shed in feces, and in places with poor sanitation, it can spread. It can also undergo genetic changes to create a form of the virus that can cause paralysis. Although this is rare, it does happen—and today there are more cases of vaccine-derived polio than wild-type polio.

It is worth noting that since 2000, more than 10 billion doses of the oral polio vaccine have been administered to almost 3 billion children. It is estimated that more than 13 million cases of polio have been prevented through these efforts. But there have been just under 760 cases of vaccine-derived polio.

We could prevent these cases by switching to the injected vaccine, which wealthy countries have already done. But that’s not easy in countries with fewer resources and those trying to reach children in remote rural areas or war zones.

Even the MMR vaccine is not entirely risk-free. Some people will experience minor side effects, and severe allergic reactions, while rare, can occur. And neither vaccine offers 100% protection against disease. No vaccine does. “Even if you vaccinate 100% [of the population], I don’t think we’ll be able to attain herd immunity for polio,” says Abbas. It’s important to acknowledge these limitations.

While there are some small risks, though, they are far outweighed by the millions of lives being saved. “[People] often underestimate the risk of the disease and overestimate the risk of the vaccine,” says Moss.

In some ways, vaccines have become a victim of their own success. “Most of today’s parents fortunately have never seen the tragedy caused by vaccine-preventable diseases such as measles encephalitis, congenital rubella syndrome, and individuals crippled by polio,” says Kimberly Thompson, president of Kid Risk, a nonprofit that conducts research on health risks to children. “With some individuals benefiting from the propagation of scary messages about vaccines and the proliferation of social media providing reinforcement, it’s no surprise that fears may endure.”

“But most Americans recognize the benefits of vaccines and choose to get their children immunized,” she adds. Now, that is a sentiment I can relate to.

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A couple of years ago, the polio virus was detected in wastewater in London, where I live. I immediately got my daughter (who was only one year old then!) vaccinated. 

Measles outbreaks continue to spring up in places where vaccination rates drop. Researchers hope that searching for traces of the virus in wastewater could help them develop early warning systems. 

Last year, the researchers whose work paved the way for the development of mRNA vaccines were awarded the Nobel Prize. Now, scientists are hoping to use the same technology to treat and vaccinate against a host of diseases.

Most vaccines work by priming the immune system to respond to a pathogen. Scientists are also working on “inverse vaccines” that teach the immune system to stand down. They might help treat autoimmune disorders.

From around the web

A person in the US is the first in the country to have become severely ill after being infected with the bird flu virus, the US Centers for Disease Control and Prevention shared on December 18. The case was confirmed on December 13. The person was exposed to sick and dead birds in backyard flocks in Louisiana. (CDC) 

Gavin Newsom, the governor of California, declared a state of emergency as the bird flu virus moved from the Central Valley to Southern California dairy herds. Since August, 645 herds have been reported to be infected with the virus. (LA Times)

Pharmacy benefit managers control access to prescription drugs for most Americans. These middlemen were paid billions of dollars by drug companies to allow the free flow of opioids during the US’s deadly addiction epidemic, an investigation has revealed. (New York Times)

Weight-loss drugs like Ozempic have emerged as blockbuster medicines over the past couple of years. We’re learning that they may have benefits beyond weight loss. Might they also protect organ function or treat kidney disease? (Nature Medicine)

Doctors and scientists have been attempting head transplants on animals for decades. Can they do it in people? Watch this delightful cartoon to learn more about the early head transplant attempts. (Aeon)

Donating embryos for research is surprisingly complex

This article first appeared in The Checkup, MIT Technology Review’s weekly biotech newsletter. To receive it in your inbox every Thursday, and read articles like this first, sign up here.

There’s a new film about IVF out on Netflix. And “everyone in the field [of reproductive medicine] has watched it,” according to one embryologist I spoke to recently. Joy is a lovely watch about the birth of the field, thanks to the persistent efforts of Robert Edwards, Jean Purdy, and Patrick Steptoe in the face of significant opposition.

The team performed much of their key research during the 1960s and ’70s. And Louise Brown, the first “test tube baby” (as she was called at the time), was born in 1978. It’s remarkable to think that within 40 years of that milestone, another 8 million babies had been born through IVF. Today, it is estimated that over 12 million babies have resulted from IVF, and that the use of reproductive technology accounts for over 2% of births in the US.

IVF is a success story for embryo research. But today, valuable embryos that could be used for research are being wasted, say researchers who gathered at a conference in central London earlier this week.

The conference was organized by the Progress Educational Trust, a UK-based charity that aims to provide information to the public on genomics and infertility. The event marked 40 years since the publication of the Warnock Report, which followed a governmental inquiry into infertility treatment and embryological research. The report is considered to be the first to guide recognition of the embryo’s “special” status in law and helped establish regulation of the nascent technology in the UK.

The report also endorsed the “14-day rule,” which limits the growth of embryos in a lab to this two-week point. The rule, since adopted around the world, is designed to prevent scientists from growing embryos to the point where they develop a structure called the primitive streak. At this point, the development of tissues and organs begins, and the embryo is no longer able to split to form twins. 

The embryos studied in labs have usually been created for IVF but are no longer needed by the people whose cells created them. Those individuals might have completed their families, or they might not be able to use the embryos because their circumstances have changed. Sometimes the embryos have genetic abnormalities that make them unlikely to survive a pregnancy.

These embryos can be used to learn more about how humans develop before birth, and to discover potential treatments for developmental disorders like spina bifida or heart defects, for example. Research on embryos can help reveal clues about our fundamental biology, and provide insight into pregnancy and miscarriage.

A survey conducted by the Human Fertility and Embryology Authority, which regulates reproductive technology in the UK, found that the majority of patients would rather donate their embryos to research than allow them to “perish,” Geraldine Hartshorne, director of the Coventry Centre for Reproductive Medicine, told the audience.

Despite this, the number of embryos donated for research in the UK has dropped steeply over the last couple of decades, from 17,925 in 2004 to 675 in 2019—a surprising decline considering that the number of IVF cycles performed increased steadily over the same period. 

There are a few reasons why embryos aren’t making it into research labs, says Hartshorne. Part of the problem is that most IVF cycles happen at clinics that don’t have links with academic research centers.

As things stand, embryos tend to be stored at the clinics where they were created. It can be difficult to get them to research centers—clinic staff don’t have the time, energy, or head space to manage the paperwork legally required to get embryos donated to specific research projects, said Hartshorne. It would make more sense to have some large, central embryo bank where people could send embryos to donate for research, she added.

A particular problem is the paperwork. While the UK is rightly praised for its rigorous approach to regulation of reproductive technologies, which embryologists around the globe tend to describe as “world-leading,” there are onerous levels of bureaucracy to contend with, said Hartshorne. “When patients contact me and say ‘I’d like to give my embryos or my eggs to your research project,’ I usually have to turn them away, because it would take me a year to get through the paperwork necessary,” she said.

Perhaps there’s a balance to be struck. Research on embryos has the potential to be hugely valuable. As the film Joy reminds us, it can transform medical practice and change lives.

“Without research, there would be no progress, and there would be no change,” Hartshorne said. “That is definitely not something that I think we should aspire to for IVF and reproductive science.”

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Scientists are working on ways to create embryos from stem cells, without the use of eggs or sperm. How far should we allow these embryo-like structures to develop? 

Researchers have implanted these “synthetic embryos” in monkeys. So far, they’ve been able to generate a short-lived pregnancy-like response … but no fetuses.

Others are trying to get cows pregnant with synthetic embryos. Reproductive biologist Carl Jiang’s first goal is to achieve a cow pregnancy that lasts 30 days. 

Several startups are using robots to fertilize eggs with sperm to create embryos. Two girls are the first people to be born after robot-assisted fertilization, says the team behind the work. 

From around the web

Mexico’s Sinaloa cartel is recruiting young chemistry students from colleges to make fentanyl. Specifically, the students are being tasked with the often dangerous job of trying to synthesize precursor chemicals that must currently be imported. They also try to design stronger versions of the drug that are more likely to get users hooked. (New York Times)

Billionaire Greg Lindberg is running his own “baby project.” Having duped, misled, and paid off a series of egg donors and surrogates, the disgraced insurance tycoon currently has 12 children, nine of whom were born in the last five years or so. He is the sole parent caring for eight of them, despite facing significant jail time since being convicted of bribery and pleading guilty to money laundering and fraud conspiracy charges for crimes unrelated to the baby project. The scale of his project is an indictment of the US fertility industry. (Bloomberg Businessweek)

The UK government has agreed to a contract for more than 5 million doses of a vaccine designed to protect people from the H5 bird flu virus. The vaccine is being procured as part of pandemic preparedness plans and will be used only if the virus starts spreading among humans. (UK Health Security Agency)

Last week, MPs voted in favor of a bill to legalize assisted dying in England and Wales. In the past few months, the debate over the bill has included horror stories of painful deaths. Most deaths are “ordinary,” but we all stand to benefit from talking about, and understanding, what death involves. (New Statesman)

An unknown disease has killed 143 people in southwest Congo, according to local authorities. The number of infections continues to rise, and the situation is extremely worrying. (Reuters)

Brian Thompson, the 50-year-old CEO of US health insurance company UnitedHealthcare, was fatally shot in New York city on Wednesday. The New York Times is reporting that bullet casings found at the scene appear to have been marked with the words “delay” and “deny.” The words may refer to strategies used by insurance companies to avoid covering healthcare costs. (New York Times)

The risk of a bird flu pandemic is rising

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How worried should we be about bird flu? It’s a question that I’ve been asked by friends and colleagues several times over the last couple of weeks. Their concerns have been spurred by some potentially worrisome developments in the US, including the continued spread of the virus among dairy cattle, the detection of the virus in a pig as well as cow’s milk, and—most concerning of all—the growing number of human infections.

I’ll admit that I’m worried. We don’t yet have any evidence that the virus is spreading between people, but the risk of a potential pandemic has increased since I last covered this topic a couple of months ago.

And once you combine that increased risk with an upcoming change in presidential administration that might leave US health agencies in the hands of a vaccine denier who promotes the consumption of raw milk, well … it’s not exactly a comforting thought.

The good news is we are in a much better position to tackle any potential future flu outbreaks than we were to face covid-19 back in 2020, given that we already have vaccines. But, on the whole, it’s not looking great.

The bird flu that is currently spreading in US dairy cattle is caused by the H5N1 virus. The virus is especially lethal to some bird populations and has been wiping out poultry and seabirds for the last couple of years. It has also caused fatal infections in many mammals who came into contact with those birds.

H5N1 was first detected in a dairy cow in Texas in March of this year. As of this week, the virus has been reported in 675 herds across 15 states, according to the US Department of Agriculture’s Animal and Plant Health Inspection Service (also known as APHIS).

Those are just the cases we know about. There may be more. The USDA requires testing of cattle before they are moved between states. And it offers a voluntary testing program for farmers who want to know if the virus is present in their bulk milk tanks. But participation in that program is optional.

States have their own rules. Colorado has required testing of bulk milk tanks in licensed dairy farms since July. The Pennsylvania Department of Agriculture announced plans for a program just last week. But some states have no such requirements.

At the end of October, the USDA reported that the virus had been detected in a pig for the first time. The pig was one of five in a farm in Oregon that had “a mix of poultry and livestock.” All the pigs were slaughtered.

Virologists have been especially worried about the virus making its way into pigs, because these animals are notorious viral incubators. “They can become infected with swine strains, bird strains and human strains,” says Brinkley Bellotti, an infectious disease epidemiologist at Wake Forest University in North Carolina. These strains can swap genes and give rise to new, potentially more infectious or harmful strains.

Thankfully, we haven’t seen any other cases in pig farms, and there’s no evidence that the virus can spread between pigs. And while it has been spreading pretty rapidly between cattle, the virus doesn’t seem to have evolved much, says Seema Lakdawala, a virologist at the Emory University School of Medicine in Atlanta, Georgia. That suggests that the virus made the leap into cattle, probably from birds, only once. And it has been spreading through herds since.

Unfortunately, we still don’t really know how it is spreading. There is some evidence to suggest the virus can be spread from cow to cow through shared milking equipment. But it is unclear how the virus is spreading between farms. “It’s hard to form an effective control strategy when you don’t know exactly how it’s spreading,” says Bellotti.

But it is in cows. And it’s in their milk. When scientists analyzed 297 samples of Grade A pasteurized retail milk products, including milk, cream and cheese, they found viral RNA from H5N1 in 20% of them. Those samples were collected from 17 states across the US. And the study was conducted in April, just weeks after the virus was first detected in cattle. “It’s surprising to me that we are totally fine with … our pasteurized milk products containing viral DNA,” says Lakdawala.

Research suggests that, as long as the milk is pasteurized, the virus is not infectious. But Lakdawala is concerned that pasteurization may not inactivate all of the virus, all the time. “We don’t know how much virus we need to ingest [to become infected], and whether any is going to slip through pasteurization,” she says.

And no reassurances can be made for unpasteurized raw milk. When cows are infected with H5N1, their milk can turn thick, yellow and “chunky.” But research has shown that, even when the milk starts to look normal again, it can still contain potentially infectious virus.

The most concerning development, though, is the rise in human cases. So far, 55 such cases of H5N1 bird flu have been reported in the US, according to the US Centers for Disease Control and Prevention (CDC). Twenty-nine of those cases have been detected in California. In almost all those cases, the infected person is thought to have caught the virus from cattle or poultry on farms. But in two of those cases, the source of the infection is unknown.

Health professionals don’t know how a teenager in British Columbia, Canada, got so sick with bird flu, either. The anonymous teenager, who sought medical care for an eye infection on November 2, is still seriously ill in hospital, and continues to rely on a ventilator to breathe. Local health officials have closed their investigation into the teen’s infection.

There may be more, unreported cases out there, too. When researchers tested 115 dairy farm workers in Michigan and Colorado, they found markers of recent infection with the virus in 7% of them.

So far, there is no evidence that the virus can spread between people. But every human infection offers the virus another opportunity to evolve into a form that can do just that. People can act as viral incubators, too. And during flu season, there are more chances for the H5N1 virus to mix with circulating seasonal flu viruses. 

“Just because we [haven’t seen human-to-human spread] now doesn’t mean that it’s not capable of happening, that it won’t happen, or that it hasn’t already happened,” says Lakdawala.

So where do we go from here? Lakdawala thinks we should already have started vaccinating dairy farm workers. After all, the US has already stockpiled vaccines for H5N1, which were designed to protect against previous variants of the virus. “We’re not taking [the human cases] seriously enough,” she says.

We need to get a better handle on exactly how the virus is spreading, too, and implement more effective measures to stop it from doing so. That means more testing of both cows and dairy farm workers at the very least. And we need to be clear that, despite what Robert F. Kennedy Jr., the current lead contender for the role of head of the US Department of Health and Human Services, says, raw milk can be dangerous, and vaccines are a vital tool in the prevention of pandemics.

We still have an opportunity to prevent the outbreak from turning into a global catastrophe. But the situation has worsened since the summer. “This is sort of how the 2009 pandemic started,” says Lakdawala, referring to the H1N1 swine flu pandemic. “We started to have a couple of cases sporadically, and then the next thing you knew, you were seeing it everywhere.”

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The US is planning to stockpile millions of doses of H5N1 vaccines. But our current approach to making flu vaccines is slow and cumbersome. New vaccines that don’t rely on the use of eggs, or make use of mRNA, might offer a better alternative.

Flu season is already underway in the US, where bird flu is spreading among cattle. That has virologists worried that a person infected with both viruses could unwittingly incubate an all-new strain of the virus.

Robert F. Kennedy Jr. has already spread harmful misinformation, pseudoscience and fringe theories about AIDS and covid-19.

Some researchers are exploring new ways to prevent the spread of H5N1 in poultry. The gene editing tool CRISPR could be used to help make chickens more resistant to the virus, according to preliminary research published last year.

From around the web

President-elect Donald Trump has chosen Jay Bhattacharya for his pick to lead the US National Institutes of Health, an agency with a $48 billion budget that oversees the majority of medical research in the country. Bhattacharya was one of three lead authors of the Great Barrington Declaration, a manifesto published in 2020 arguing against lockdowns during the height of the covid-19 pandemic, and supporting a “let it rip” approach instead. (STAT)

An IVF mix up left two families raising each other’s biological babies. They didn’t realize until the children were a couple of months old. What should they do? (Have the tissues ready for this one, which is heartbreaking and heartwarming in equal measure) (New York Times)

Why do we feel the need to surveil our sleeping babies? This beautiful comic explores the various emotional pulls experienced by new parents. (The Verge)

Australia’s parliament has passed a law that bans children under the age of 16 from using social media. Critics are concerned that the law is a “blunt instrument” that might drive young teens to the dark web, or leave them feeling isolated. (The Guardian)

Lab-grown foie gras, anyone? Cultivated meat is going high-end, apparently. (Wired)

Who should get a uterus transplant? Experts aren’t sure.

This article first appeared in The Checkup, MIT Technology Review’s weekly biotech newsletter. To receive it in your inbox every Thursday, and read articles like this first, sign up here.

Earlier this year, a boy in Sweden celebrated his 10th birthday. Reproductive scientists and doctors marked the occasion too. This little boy’s birth had been special. He was the first person to be born from a transplanted uterus.

The boy was born in 2014 after his mother, a 35-year-old woman who had been born without a uterus, received a donated uterus from a 61-year-old close family friend. At the time, she was one of only 11 women who had undergone the experimental procedure.

A decade on, over 135 uterus transplants have been performed globally, resulting in the births of over 50 healthy babies. The surgery has had profound consequences for these families—the recipients would not have been able to experience pregnancy any other way.

But legal and ethical questions continue to surround the procedure, which is still considered experimental. Who should be offered a uterus transplant? Could the procedure ever be offered to transgender women? And if so, who should pay for these surgeries?

These issues were raised at a recent virtual event run by Progress Educational Trust, a UK-based charity that aims to provide information to the public on genomics and infertility. One of the speakers was Mats Brännström, who led the team at the University of Gothenburg that performed the first successful transplant.

For Brännström, the story of uterus transplantation begins in 1998. While traveling in Australia, he said, he met a 27-year-old woman called Angela, who longed to be pregnant but lacked a functional uterus. She suggested to Brännström that her mother could donate hers. “I was amazed I hadn’t thought of it before,” he said.

According to Brännström, around 1 in 500 women experience infertility due to what’s known as absolute uterine factor infertility, or AUFI, meaning they do not have a functional uterus. Uterus transplants could offer them a way to get pregnant.

His meeting with Angela kick-started a research project that started in mice and eventually moved on to pigs, sheep, and baboons. Brännström’s team started performing uterus transplants in women as part of a small clinical trial in 2012. In that trial, all the donors were living, and in many cases they were the mothers or aunts of the recipients.

The surgeries ended up being more complicated than he had anticipated, said Brännström. The operation to remove a donor’s uterus was expected to take between three and four hours. It ended up taking between eight and 11 hours.  

In that first trial, Brännström’s team transplanted uteruses into nine women, each of whom had IVF to create and store embryos beforehand. The woman who was the first to give birth had IVF over a 12-month period, which ended six months before her surgery. It took a little over 10 hours to remove the uterus from the donor, and just under five hours to stitch it into the recipient.

The recipient started getting her period 43 days after her transplant. Doctors transferred one of her embryos into the uterus a year after her surgery. Three weeks later, a pregnancy test confirmed she was pregnant.

At 31 weeks, she was admitted to hospital with preeclampsia, a serious medical condition that can develop during pregnancy, and her baby was delivered by C-section 16 hours later. She was discharged from hospital after three days, although the baby spent 16 days in the hospital’s neonatal unit.

Despite those difficulties, her story is considered a success. Other uterus recipients have also experienced pregnancy complications, and some have had surgical complications. And all transplant recipients must adhere to a regimen of immunosuppressant drugs, which can have side effects.

The uteruses aren’t intended to last forever, either. Surgeons remove them once the recipients have completed their families, often after one or two children. The removal is also a significant operation.

Given all that, uterus transplants are not to be taken lightly. And there are other paths to parenthood. Some ethicists are concerned that in pursuing uterus transplantation as a fertility treatment, we might reinforce ideas that define a woman’s value in terms of her reproductive potential, Natasha Hammond-Browning, a legal scholar at Cardiff University in Wales, said at the event. “There is debate around whether we should be giving greater preference to adoption, to surrogacy, and to supporting children who already exist and who need care,” she said.

We also need to consider whether there is a “right to gestate,” and if there is, who has that right, said Hammond-Browning. And these concerns need to be balanced with the importance of reproductive autonomy—the idea that people have the right to decide and control their own reproductive efforts.

Further questions remain over whether uterus transplants might ever be an option for trans women, who not only lack a uterus but also have a different pelvic anatomy. I asked the speakers if the surgery might ever be feasible. They weren’t hugely optimistic that it would, at least in the near future.

“I personally think that the transgender community have been given … false hope for responsible transplantation in the near future,” was the response of J. Richard Smith of Imperial College London, who co-led the first uterus transplant performed in the UK. Even cisgender women who have needed surgery to create “neovaginas” aren’t eligible for the uterus transplants his team are offering as part of a clinical study. They have an altered vaginal microbiome that appears to increase the risk of miscarriage, he said.

“There is a huge amount of work to be done before this work can be translated to the transgender community,” Smith said. Brännström agreed but added that he thinks the surgery will be available at some point—just after a lot more research.

And then there are the legal and ethical questions, none of which have easy answers. Hammond-Browning pointed out that clinical teams would first need to determine what the goal of such an operation would be. Is it about reproduction or gender realignment, for example? And how might that goal influence decisions over who should get a donated uterus, and why?

Considering only 135 human uterus transplants have ever been carried out, we still have a lot to learn about the best way to perform them. (For context, more than 25,000 kidney transplants were carried out in 2023 in the US alone.) Researchers are still figuring out how uteruses from deceased donors differ from those of living ones, and how to minimize complications in young, healthy women. Since that little boy was born 10 years ago, only 50 other children have been born in a similar way. It’s still early days.

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The first birth following the transplantation of a uterus from a dead donor happened in 2017. A team in Brazil transferred the uterus of a 45-year-old donor, who had died from a brain hemorrhage, to a 32-year-old recipient born without a uterus. 

Researchers are working on artificial wombs—“biobags” designed to care for premature babies. They have been tested on lambs and piglets. Now FDA advisors are figuring out how to move the technology into human trials. 

An alternative type of artificial womb is being used to grow mouse embryos. Jacob Hanna at the Weizmann Institute of Science and his colleagues say they’ve been able to grow embryos in this environment for 11 or 12 days—around half the animal’s gestational period. 

Research is underway to develop new fertility options for transgender men. Some of these men are put off by existing approaches, which tend to involve pausing hormone therapy and undergoing potentially distressing procedures. 

From around the web

People on Ozempic, Wegovy, and similar drugs are losing their appetite for sugary, ultraprocessed foods. The food industry will have to adapt. (TIL Nestlé has already started a line of frozen meals targeted at people on these weight-loss drugs.) (The New York Times Magazine)

People who have a history of obesity can find it harder to lose weight. That might be because the fat cells in our bodies seem to “remember” that history and have an altered response to food. (The Guardian)

Robert F. Kennedy Jr. took leave as chairman of Children’s Health Defense, a nonprofit known for spreading doubt about vaccines, to run for US president last year. But he is still involved in legal cases filed by the group. And several of its cases remain open, including ones against the Food and Drug Administration, the Centers for Disease Control and Prevention, and the National Institutes of Health—all agencies Kennedy would lead if his nomination for head of Health and Human Services is confirmed. (STAT)

Researchers are among the millions of new users of Bluesky, a social media alternative to X (formerly known as Twitter). “There is this pent-up demand among scientists for what is essentially the old Twitter,” says one researcher who found that the number of influential scientists using the platform doubled between August and November. (Science) 

Since 2016, a team of around 100 scientists have been working to catalogue the 37 trillion or so cells in the human body. This week, the Human Cell Atlas published a collection of studies that represents a significant first step toward that goal—including maps of cells in the nervous system, lungs, heart, gut, and immune system. (Nature)

Why the term “women of childbearing age” is problematic

This article first appeared in The Checkup, MIT Technology Review’s weekly biotech newsletter. To receive it in your inbox every Thursday, and read articles like this first, sign up here.

Every journalist has favorite topics. Regular Checkup readers might already know some of mine, which include the quest to delay or reverse human aging, and new technologies for reproductive health and fertility. So when I saw trailers for The Substance, a film centered on one middle-aged woman’s attempt to reexperience youth, I had to watch it.

I won’t spoil the movie for anyone who hasn’t seen it yet (although I should warn that it is not for the squeamish, or anyone with an aversion to gratuitous close-ups of bums and nipples). But a key premise of the film involves harmful attitudes toward female aging.

“Hey, did you know that a woman’s fertility starts to decrease by the age of 25?” a powerful male character asks early in the film. “At 50, it just stops,” he later adds. He never explains what stops, exactly, but to the viewer the message is pretty clear: If you’re a woman, your worth is tied to your fertility. Once your fertile window is over, so are you.

The insidious idea that women’s bodies are, above all else, vessels for growing children has plenty of negative consequences for us all. But it has also set back scientific research and health policy.

Earlier this week, I chatted about this with Alana Cattapan, a political scientist at the University of Waterloo in Ontario, Canada. Cattapan has been exploring the concept of “women of reproductive age”—a descriptor that is ubiquitous in health research and policy.

The idea for the research project came to her when the Zika virus was making headlines around eight years ago. “I was planning on going to the Caribbean for a trip related to my partner’s research, and I kept getting advice that women of reproductive age shouldn’t go,” she told me. At the time, Zika was being linked to microcephaly—unusually small heads—in newborn babies. It was thought that the virus was affecting key stages of fetal development.

Cattapan wasn’t pregnant. And she wasn’t planning on becoming pregnant at the time. So why was she being advised to stay away from areas with the virus?

The experience got her thinking about the ways in which attitudes toward our bodies are governed by the idea of potential pregnancy. Take, for example, biomedical research on the causes and treatment of disease. Women’s health has lagged behind men’s as a focus of such work, for multiple reasons. Male bodies have long been considered the “default” human form, for example. And clinical trials have historically been designed in ways that make them less accessible for women.

Fears about the potential effects of drugs on fetuses have also played a significant role in keeping people who have the potential to become pregnant out of studies. “Scientific research has excluded women of ‘reproductive age,’ or women who might potentially conceive, in a blanket way,” says Cattapan. “The research that we have on many, many drugs does not include women and certainly doesn’t include women in pregnancy.”  

This lack of research goes some way to explaining why women are much more likely to experience side effects from drugs—some of them fatal. Over the last couple of decades, greater effort has been made to include people with ovaries and uteruses in clinical research. But we still have a long way to go.

Women are also often subjected to medical advice designed to protect a potential fetus, whether they are pregnant or not. Official guidelines on how much mercury-containing fish it is safe to eat can be different for “women of childbearing age,” according to the US Environmental Protection Agency, for example.  And in 2021, the World Health Organization used the same language to describe people who should be a focus of policies to reduce alcohol consumption. 

The takeaway message is that it’s women who should be thinking about fetal health, says Cattapan. Not the industries producing these chemicals or the agencies that regulate them. Not even the men who contribute to a pregnancy. Just women who stand a chance of getting pregnant, whether they intend to or not. “It puts the onus of the health of future generations squarely on the shoulders of women,” she says.

Another problem is the language itself. The term “women of reproductive age” typically includes women between 15 and 44. Women at one end of that spectrum will have very different bodies and a very different set of health risks from those at the other. And the term doesn’t account for people who might be able to get pregnant but don’t necessarily identify as female.

In other cases it is overly broad. In the context of the Zika virus, for example, it was not all women between the ages of 15 and 44 who should have considered taking precautions. The travel advice didn’t apply to people who’d had hysterectomies or did not have sex with men, for example, says Cattapan. “Precision here matters,” she says. 

More nuanced health advice would be helpful in cases like these. Guidelines often read as though they’re written for people assumed to be stupid, she adds. “I don’t think that needs to be the case.”

Another thing

On Thursday, president-elect Donald Trump said that he will nominate Robert F. Kennedy Jr. to lead the US Department of Health and Human Services. The news was not entirely a surprise, given that Trump had told an audience at a campaign rally that he would let Kennedy “go wild” on health, “the foods,” and “the medicines.”

The role would give Kennedy some control over multiple agencies, including the Food and Drug Administration, which regulates medicines in the US, and the Centers for Disease Control and Prevention, which coordinates public health advice and programs.

That’s extremely concerning to scientists, doctors, and health researchers, given Kennedy’s positions on evidence-based medicine, including his antivaccine stance. A few weeks ago, in a post on X, he referred to the FDA’s “aggressive suppression of psychedelics, peptides, stem cells, raw milk, hyperbaric therapies, chelating compounds, ivermectin, hydroxychloroquine, vitamins, clean foods, sunshine, exercise, nutraceuticals and anything else that advances human health and can’t be patented by Pharma.”  

“If you work for the FDA and are part of this corrupt system, I have two messages for you,” continued the post. “1. Preserve your records, and 2. Pack your bags.”

There’s a lot to unpack here. But briefly, we don’t yet have good evidence that mind-altering psychedelic drugs are the mental-health cure-alls some claim they are. There’s not enough evidence to support the many unapproved stem-cell treatments sold by clinics throughout the US and beyond, either. These “treatments” can be dangerous.

Health agencies are currently warning against the consumption of raw unpasteurized milk, because it might carry the bird flu virus that has been circulating in US dairy farms. And it’s far too simplistic to lump all vitamins together—some might be of benefit to some people, but not everyone needs supplements, and high doses can be harmful.

Kennedy’s 2021 book The Real Anthony Fauci has already helped spread misinformation about AIDS. Here at MIT Technology Review, we’ll continue our work reporting on whatever comes next. Watch this space.

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The tech industry has a gender problem, as the Gamergate and various #MeToo scandals made clear. A new generation of activists is hoping to remedy it. 

Male and female immune systems work differently. Which is another reason why it’s vital to study both women and female animals as well as males. 

Both of the above articles were published in the Gender issue of MIT Technology Review magazine. You can read more from that issue online here.

Women are more likely to receive abuse online. My colleague Charlotte Jee spoke to the technologists working on an alternative way to interact online: a feminist internet.

From around the web 

The scientific community and biopharma investors are reacting to the news of Robert F. Kennedy Jr.’s nomination to lead the Department of Health and Human Services. “It’s hard to see HHS functioning,” said one biotech analyst. (STAT)

Virologist Beata Halassy successfully treated her own breast cancer with viruses she grew in the lab. She has no regrets. (Nature)

Could diet influence the growth of endometriosis lesions? Potentially, according to research in mice fed high-fat, low-fiber “Western” diets. (BMC Medicine)

Last week, 43 female rhesus macaque monkeys escaped from a lab in South Carolina. The animals may have a legal claim to freedom. (Vox)