In 2019, the AI researcher Rich Sutton published a short essay called “The Bitter Lesson.” Seventy years of AI research, he argued, kept demonstrating the same thing: The most effective ways to train AI rely on raw, brute-force computing power — simply scaling up — rather than clever approaches built on human insight. It didn’t matter how elegant the researchers’ work was. More compute would win every time. It’s a bitter lesson because, well, no one wants to accept that even the best efforts can go unrewarded.

This summer, climate change has been teaching its own kind of bitter lesson. Last week smoke from out-of-control Canadian wildfires reached more than 120 million Americans, sending out air quality alerts across 18-plus states from Minnesota to Virginia. Those wildfires, which were made more likely by the effects of climate change, followed record-breaking heat waves in Europe that contributed to the deaths of thousands of people.

Disasters like these inevitably renew calls for climate action, but no current US emissions policy, no amount of carbon cutting now, could clear the air, just as nothing Europe has done on climate — and it has done more than any other region, at no small cost — could protect it from those killer temperatures. Not this summer, not this decade, not the one after. The steps countries take now to reduce carbon emissions, to mitigate climate change, will not protect them from the present-day effects of climate change.

That’s the bitter lesson of climate change, and 2026 is the summer it has become unignorable. The dangerous effects we’ve been warned about are here, locked in on every timescale that matters to the people living through them. We can’t prevent the worst from happening right now, so we need to figure out how we’re going to adapt to it. 

The smoke we can’t stop

Canadian wildfire smoke is as close to an unstoppable disaster as exists today. The fires are Canada’s, the ignition is mostly lightning, the fuel is a subcontinent of boreal forest no fire agency can manage, and the whole system sits outside US jurisdiction. While strategies like prescribed burning and forest thinning can help reduce the wildfires that crop up in the western US, the sheer scale of Canadian forests makes such management far more difficult, maybe impossible. There is no timescale on which American mitigation clears American air of Canadian wildfire smoke. 

What this means is that for this wildfire smoke, at this moment, adaptation may be all there is.

American law has already conceded the point. Under the Clean Air Act’s Exceptional Events Rule, a state can petition the Environmental Protection Agency to strike wildfire-smoke days from the record used to judge whether its air is legally clean. In other words, the official response to one of the country’s fastest-growing air-quality threats is to delete it from the ledger. 

It’s true that climate attribution science ties heat waves to warming with the highest confidence of any extreme, while wildfire is messier — a compound event filtered through ignition, fuel, and fire weather. But fire seasons are lengthening, fuels are drying, and the most extreme wildfire events on Earth more than doubled between 2003 and 2023. The pattern is intensifying fire in particular regions — the boreal north among them — and the smoke goes where the wind says.

And that smoke is worse than it looks. Wildfire PM2.5 — the microscopic particles that are particularly dangerous —  is roughly three to four times more toxic to the lungs, per unit of mass, than ordinary urban particulate matter. During major smoke events, pediatric asthma visits can spike by more than 30 percent, and Harvard researchers have found the cardiorespiratory damage persists for months after the sky turns blue again. That’s especially dangerous for vulnerable populations like babies and pregnant women.

We can’t affect the winds, we struggle to stop the fires, and any current attempt to reduce warming enough to make those infernos less likely won’t be felt for years. But that doesn’t mean we’re helpless to protect ourselves from wildfire smoke, any more than we are from extreme heat.

We can purify indoor air, and it costs less than you probably think. Strap four furnace filters to a box fan — creating a Corsi-Rosenthal box — and indoor PM2.5 drops by roughly half; in testing during actual wildfire smoke, a DIY unit cut fine particles by about 56 percent in a large room and close to 99 percent in a small sealed one.

For heat, the toolkit is even better known — and one of the best proofs it works is in, of all places, France. The historic 2003 heat wave killed some 15,000 people there, most of them elderly and alone. The national heat plan built in its aftermath — tiered alerts, registries of vulnerable residents, check-in calls, cool rooms — cut the death toll of comparable heat waves by roughly 90 percent: When France hit its all-time record of 114.8°F in 2019, fewer than 1,500 died, per the Christian Science Monitor. A recent European analysis estimates a rerun of 2003 would now kill 77 percent fewer people in France than in a world that never adapted.

So technologies exist to protect ourselves. What’s too often missing are the standards, money, and the drive to deploy protection before the disaster arrives instead of after.

Catching up to today

When it comes to wildfire smoke, some governments are ahead of the game — and some aren’t. Washington state, Oregon, and California now regulate outdoor workers’ smoke exposure by air-quality index, under rules like Cal/OSHA’s wildfire-smoke standard; California funds “clean air centers” with upgraded filtration where people can shelter on bad-air days; Colorado’s Clean Air for Schools program ships free HEPA units to K-12 classrooms. A purifier humming in a classroom is essentially doing for smoke what a cooling center does for heat.

When it comes to heat, some parts of Europe are catching up. Barcelona now runs a network of nearly 400 “climate shelters” — libraries, museums, retrofitted schoolyards — with the goal of putting one within a 10-minute walk of every resident. For the first time, the city is keeping libraries open through August to do it, which, as anyone who has visited Europe in the late summer knows, is no small thing.

So adaptation exists, and it is saving lives. But this summer has also shown what happens when cities, states, and countries aren’t ready. 

In the US, the Midwestern and Northeastern states that spent last week under smoke alerts have almost none of the protections against wildfire smoke that have become more common in Western states, and no one is required to build them, because the country has no enforceable national indoor air-quality standard at all. In Europe, national heat plans are still reluctant to reach for the most powerful tool on the shelf. About one European household in five has air conditioning, compared to nearly nine in ten in the US, in large part because much of the continent still treats the machine as a moral defect. 

In both cases, rich regions that have largely taken climate mitigation more seriously than some of their neighbors aren’t pursuing adaptations they need. Which really means not taking climate change as seriously as they should. 

Accepting the bitter lesson

For a generation, adaptation was the word climate advocates were often reluctant to say out loud. In his 1992 book Earth in the Balance, Al Gore called adaptation “a kind of laziness, an arrogant faith in our ability to react in time to save our skins.” (He later changed his mind.) And in fairness, “we’ll just adapt” has often been a delaying tactic, an easy out for polluters. 

But the ground has shifted under that caution, because the projections did exactly what projections are supposed to do: they came true. 

Longer fire seasons, deadlier heat waves, smoke reaching places that never used to see it — this summer is the confirmation. And that changes what seriousness requires. If you’ve spent decades warning people that the effects of climate change are coming, you can’t treat readying for those effects as a distraction from the real work. None of this argues for easing up on emissions — each ton that isn’t emitted is adaptation nobody has to build. But preparing for what you predicted is what believing your own prediction looks like.

For AI researchers, Rich Sutton’s lesson was bitter for a specific reason. Those who resisted its conclusion weren’t foolish; they resisted it because it seemed to undercut all their hard work. They resisted it because it didn’t seem fair, just as it’s not fair that countries and states that have in many ways done much to mitigate climate change find themselves just as vulnerable, if not more so, than peers that have done comparatively little. 

But here’s the other half of Sutton’s lesson: The researchers who accepted it won. They stopped defending their cleverness and built what worked. That option is open to climate politics too. The atmosphere isn’t fair, but it is consistent, and it will deliver next summer’s version of this one on schedule. We can be ready. The bitter lesson is only bitter until you have the will to act on it. 

A version of this story originally appeared in the Future Perfect newsletter. Sign up here!

In January 2025, Linda-Gail Bekker stood inside a vaccine manufacturing plant and allowed herself to believe that the first HIV vaccine candidate conceived through African science and led by Africans might finally become a reality.

The vaccine would be built on mRNA technology, the same platform that had helped tame the Covid-19 pandemic. Bekker hoped it might finally crack the puzzle that had frustrated HIV researchers for more than four decades.

No virus has proved more evasive. Hundreds of HIV vaccines have entered testing; none has succeeded at providing durable protection against infection. And the need remains vast: In 2025, roughly 1.2 million new HIV infections were reported; anti-retroviral treatments have turned it into more of a survivable disease, but more than half a million people died from AIDS-related causes the same year. There is still no known cure.

So researchers like Bekker, an infectious disease specialist at the University of Cape Town, have more hope now, in part because there is finally a clearer idea of what an effective vaccine needs to do. It must coax the immune system into producing a particular type of protective antibody, a rare class of defender, capable of recognizing and disabling HIV despite the virus’s extraordinary diversity and rapid ability to mutate.

No one yet knows how to reliably do that. But mRNA is uniquely suited to the task of finding out, vaccinologists say. Thanks to the platform’s speed and flexibility, researchers can iterate rapidly through the otherwise laborious process of designing, testing, and refining the series of vaccine components needed to guide the body toward making those essential antibodies.

At the start of last year, Bekker and her colleagues were ready to put that strategy to the test. The clinical trial for their new mRNA-based HIV vaccine was just on the verge of enrolling its first participants. But the project depended on the same backing that had sustained HIV vaccine research for decades: US government funding. Washington had long supplied roughly 90 percent of the world’s investment in the field. Then President Donald Trump returned to office.

Within hours of his inauguration, Trump signed an executive order freezing foreign aid. The $45 million contract from the US Agency for International Development (USAID) that was supposed to fund clinical trials like Bekker’s disappeared, as did a web of other funds, many routed through the National Institutes of Health (NIH), that had helped fuel the field’s progress for years.

The timing could hardly be more cruel. After 40-odd years of chasing a shape-shifting foe, scientists believe they now know what kind of immune response an HIV vaccine must generate — and have in mRNA a powerful new tool for pursuing it. But just as many researchers have finally glimpsed a path to victory, the United States and much of the funding has pulled away from the fight. 

Pushing the envelope

From the outset, the target for preventing HIV was clear. Within a year of identifying the virus as the cause of AIDS in 1983, researchers had zeroed in on its envelope protein as the most promising point of attack for a vaccine.

Protruding from the virus’s surface in knobby clusters, the envelope protein acts like a molecular grappling hook, latching onto immune cells before pulling the virus itself inside. Without this feature, HIV cannot infect a cell.

Much as the coronavirus spike protein would later become the basis for Covid vaccines, this protein on the surface of HIV seemed an obvious bullseye. But identifying the target didn’t mean researchers could hit it. Most of what the immune system sees of the envelope protein is actually just a decoy. The parts that stick out and draw the strongest immune response are also its most changeable, differing from one strain to the next and mutating freely whenever antibodies close in, leaving the body to waste its firepower on a target that keeps slipping away.

Candidate vaccines kept making the same mistake. They would elicit plenty of antibodies, but not the kind that could keep up with the virus. Time and again, promising candidate vaccines generated excitement in the laboratory, only to come up empty when it mattered most in large-scale clinical testing.

The field’s fortunes started to change in the late 2000s when researchers began studying the small fraction of people living with HIV who developed antibodies capable of recognizing the virus’s concealed, conserved features. Though these hard-won antibodies came too late to protect their makers, they gave scientists a molecular blueprint for the defenses a vaccine would need to build.

As the field came to learn, these “broadly neutralizing antibodies” do not appear overnight but rather after years of battle with the virus. 

The challenge, then, was to design a vaccine that would not just trigger an immune response but guide a person’s immune system through the same evolutionary journey. This would require a succession of vaccine components to prompt a carefully choreographed process within the body, rather than the single, fixed target that suffices for shots against measles or hepatitis B.

It was a strategy rooted in rational design but dependent on trial and error. Progress would come through a steady stream of small proof-of-concept studies, each informing the next generation of vaccine candidates. Ordinarily, it would take at least a year — often longer — to manufacture and prepare each vaccine iteration before it could be tested in people. 

But then the Covid pandemic rocketed mRNA into the spotlight.

The mRNA advantage

mRNA technology upends the old recipe of vaccine development. Conventional shots work by showing the immune system a mugshot of the enemy: a killed or weakened germ, or one of its proteins, grown batch by batch in vats of cells or eggs. An mRNA vaccine takes a different route. Rather than supplying the mugshot, it supplies the instructions to draw one: a short, lab-printed strip of messenger RNA, the molecule cells normally use to ferry genetic directions from DNA to their protein-making machinery.

Inject the right sequence, and it will program the body’s own cells to become tiny factories, producing the target protein and presenting it to the immune system as if it were the real intruder. Because it is all just code, refining a design means editing text, not rebuilding a factory — the work of days, not months.

“We’ve been able to design vaccines in real time,” said University of Pennsylvania Perelman School of Medicine assistant professor Ted Kreider, who is a specialist in infectious diseases.

To HIV researchers, the appeal was obvious. HIV’s greatest weapon was its ability to shift and adapt. Now, at last, a vaccine could, too. 

The timing was ideal. Just as researchers were beginning to map the path to an effective vaccine, mRNA offered a way to move down that path at speed. With vaccine designs no longer bottlenecked by design and manufacturing, what once might have taken decades of stepwise vaccine development could, thanks to mRNA, be compressed into years.

Across a growing number of clinical trials, researchers are now testing different vaccine components, different sequences, and different delivery platforms, searching for the combination that most effectively nudges the immune system toward a truly HIV-thwarting response.

A paper published last month in Nature offered one such path forward, showing in monkeys that a painstaking sequence of eight shots could coax the immune system into producing potent antibodies capable of neutralizing a broad range of HIV strains. But even the study’s authors see a catch. “It’s still too many [shots] to be practical in humans,” said Dennis Burton, a professor of immunology and microbiology at Scripps Research who worked on the project.

Whether mRNA ultimately becomes the vaccine itself — or simply the tool that helps researchers discover it — remains an open question.

The fundamental challenge for now, after all, is vaccine design, notes Mark Feinberg, president and CEO of IAVI, a nonprofit research organization focused on developing vaccines against HIV. And for that task, he says, “the most obvious advantage of mRNA is simply the speed of getting an idea from the laboratory to the clinic.”

But if the technology reaches the finish line, researchers say it could offer other advantages as well. Because the protein is made inside the body’s own cells rather than in a lab, it folds and displays itself much as it would on the real virus, giving the immune system a more faithful target to train against. That way, when the real virus arrives, the body already knows its true face.

It also gives vaccine designers an unusual number of knobs to turn, notes Kristie Bloom, an mRNA vaccine researcher and molecular biologist at the University of Witwatersrand in South Africa. By altering the vaccine’s formulation, dose, or genetic design, researchers can shape not just the magnitude of the immune response but also its balance: favoring antibody-producing B cells, virus-killing T cells, or some mix of the two.

With mRNA, “there’s quite a bit of flexibility,” she said.

Not so fast

For all the putative upsides, however, mRNA does carry some baggage. There are concerns about public acceptance given the intense backlash and misinformation campaigns that followed the rollout of Covid-19 vaccines. And though those shots ultimately proved remarkably safe, with very low rates of serious side effects, a peculiar skin problem has emerged in early-stage trials of mRNA vaccine candidates for HIV specifically. 

In two separate trials reported last year, around one in 12 participants who received mRNA-based HIV vaccines manufactured by Moderna developed chronic urticaria, a form of persistent hives that in some cases endured for years. The vaccines encoded different portions of HIV’s envelope protein, yet both produced the same unexpected side effect.

The fact that the reactions appeared across distinct vaccine designs — but never before in Moderna’s other mRNA vaccine programs — has fueled suspicion that something about HIV’s envelope protein itself may be involved. Even so, no clear explanation has emerged. 

“We’ve ruled a bunch of things out,” said William Schief, a professor at Scripps Research’s department of immunology and microbiology who doubles as vice president for protein design at Moderna, “but there’s no smoking gun.”

Schief is continuing to investigate the source of the immune reactions. But not wanting an unresolved safety signal to bring the program to a halt, he and his collaborators have pressed ahead with lower-dose versions of the vaccine, betting that the hives will fade while the desired immune response remains intact. 

That strategy is now being evaluated in an IAVI-backed trial led by Bekker in South Africa. Known as IAVI G004, it has yielded encouraging early results. (Unlike the African-developed vaccine whose launch was derailed by the USAID funding freeze, this study is testing a different mRNA vaccine candidate, manufactured by Moderna.)

At the lowest dose tested, just one-tenth of the amount used in the original studies, the hives that had troubled earlier trials never materialized, Bekker said. Her team has since moved on to a somewhat higher dose, seeking the sweet spot between safety and immune potency. 

All of these discoveries and challenges along the way have helped map a path forward. “We know what we need to do,” said Barton Haynes, director of the Human Vaccine Institute at the Duke University School of Medicine. The task for them now is to move through the necessary iterations as quickly as the science — and the funding and political landscape — allow.

“A black hole”

When Bekker and her team learned about the sudden funding cut that would halt their African-designed, USAID-funded vaccine study in January 2025, they were already in Tanzania to prepare its launch. They immediately had to stop work on the project, which had been years in the making. “It was like falling into a black hole of depression,” she said. 

And the setbacks kept coming. With prominent vaccine critic Robert F. Kennedy Jr. overseeing US health policy, the federal government moved to undermine both vaccine science broadly and mRNA technology in particular.

The NIH, in addition to terminating dozens of smaller HIV-related grants, began winding down its flagship Consortia for HIV/AIDS Vaccine Development (CHAVD) program, which has long served as a cornerstone of global HIV vaccine research, while other federal agencies curtailed support for mRNA vaccine projects across multiple disease areas.

At the same time, South Africa, the continent’s leading center for biomedical research, found itself in the Trump administration’s crosshairs over allegations of anti-white discrimination. New federal research grants were no longer permitted to support collaborations with South African scientists, severing ties that had underpinned years of international HIV research.

“That’s a perfect storm to prevent us from building on the most exciting science HIV vaccines have had in 45 years,” said Mitchell Warren, executive director of AVAC, a nonprofit dedicated to HIV prevention access and policy. 

Yet for all the financial and political disruption, the scientific momentum hasn’t stopped. Philanthropic organizations and governments elsewhere have stepped up to help fill the funding gap, allowing key trials to move forward, although in scaled-down forms with more modest ambitions. 

The Africa-led effort that Bekker had dreamed of was salvaged, with emergency backing from the South African Medical Research Council, albeit in diminished form and built, in the end, on the same protein-based technology that mRNA was meant to leapfrog.

The only mRNA-based HIV vaccine study that is actually underway in Africa is IAVI G004: a program designed by US scientists, not by locals, and funded largely by the Gates Foundation.

A longtime backer of HIV research, that foundation is estimated to invest around $70 million annually — with $64 million being invested in 2022, and $70 million in 2026 — across a global portfolio of HIV vaccine programs. That’s a substantial sum, though only a fraction of the hundreds of millions of dollars once provided by the NIH, USAID, and other federal agencies. 

For now, some of that funding continues to flow. But even what remains is far from assured. The Trump administration’s proposed 2026 budget would slash the National Institute of Allergy and Infectious Diseases — the NIH institute that has long anchored HIV vaccine science — along with the Office of AIDS Research that coordinates HIV research across the entire NIH, leaving the field’s longer-term future in doubt.

“We’re not going to be able to fill the gap that’s been left by the US government,” said Nina Russell, director of TB & HIV research and development at the Gates Foundation. Still, she says, the foundation remains determined to keep the most promising vaccine programs moving forward: “We are super committed to it.”

All of these changes have left the research field daunted, but not hopeless. “It’s been a very disruptive time,” said Burton, who leads one of the CHAVD research hubs. But he remains convinced the field is on the right track. “The pieces of the puzzle are in place,” he said. “It’s obviously been a long, long journey, but you can begin to see the end.”

A higher bar

The funding crisis and political challenges are not the only forces reshaping HIV vaccine development.

For much of the HIV epidemic, which has killed over 40 million people worldwide, even a partially effective vaccine might have been enough to transform the course of HIV. Today, however, vaccine researchers are also competing against long-acting preventive drugs that can protect people for months at a time with just two injections. 

These drugs are an enormous step forward for HIV protection, but they also raise the standard the vaccine field must meet, Warren said. “The bar for a licensed vaccine that is going to have a public health impact has gotten much higher,” he said.

But these prophylactic drugs, which began as daily pills and have evolved into long-acting injectables, are only as good as the systems that deliver them. Cost, stigma, and the need for regular clinic visits have limited access in many countries with the highest HIV burdens. A vaccine, by contrast, that provided years of protection after a handful of doses could overcome many of those barriers.

That is precisely why many scientists view the current retreat of the US government with such alarm. After decades of disappointments and billions of dollars in investment, the field finally believes it has a coherent strategy for building an effective HIV vaccine. The fear is that momentum could stall just as researchers have begun to see a path across the finish line. As a result, what once seemed like a scientific problem increasingly looks like a political one.

For Bekker, the current moment feels all too familiar. In the early 2000s, South Africa’s government embraced AIDS denialism, delaying the rollout of lifesaving treatments and forcing researchers and clinicians to battle both the virus and the state. A quarter-century later, she says, the political opponent has merely changed address to Washington, DC, threatening once again to undermine the fight against HIV and cost countless lives.

“When politics interferes in science,” Bekker said, “that is the death of scientific progress.”

Bekker still does not know whether the vaccine she watched being manufactured last year will ever reach the people it was designed to protect. She and her colleagues still hope to carry out the made-in-Africa mRNA vaccine trial they spent years designing — if they can find a way to pay for it. But Bekker remains convinced that the scientific strategy behind it is the right one, and that mRNA may yet do for HIV what it did for Covid-19, rapidly transforming decades of scientific groundwork into an effective shot.

She only hopes politics does not succeed where HIV itself has failed in slowing the field’s progress. “We should only be fighting the virus,” Bekker said. “But we’re fighting the administration and its policies, and that is a waste of our energy.”

If the US wanted to be the world’s police officer, then why not try to be its doctor too? 

Just two months before the invasion of Iraq in 2003, George W. Bush announced an ambitious plan to pump $15 billion into the global fight against HIV, stunning his allies in Congress, health advocates, and heads of state of the program’s intended beneficiaries. 

The President’s Emergency Plan for AIDS Relief, or PEPFAR, was the largest commitment by any nation in history dedicated to addressing a single disease, a disease that killed about 3 million people in 2003, most of them living in sub-Saharan Africa, and infected 5 million more. “Ladies and gentlemen,” Bush proclaimed in his State of the Union address that year, “seldom has history offered a greater opportunity to do so much for so many.”

On that, he was right. In the two decades to follow, PEPFAR would save an astounding 25 million people’s lives through lifesaving HIV therapies, and prevent millions of babies from being born with HIV in the first place, all at a cost of about 0.08 percent of the federal budget. 

And yet, in the wake of the Trump administration’s foreign aid cuts, one of the greatest achievements in American history is now at risk. PEPFAR, mercifully, still exists, saved from the sledgehammer by an outpouring of bipartisan support last February. But experts say the program has been transformed beyond recognition by countless small cuts, and the abrupt gutting of global health architecture, reshaped not by decades of accumulated wisdom around HIV prevention, but by at times absurdly petty ideology.

Over the past year, more than 77 percent of PEPFAR grantees have lost funding or had their payments delayed, according to a survey released Tuesday by the HIV research group amfAR. 

Nearly two-thirds of grantees — especially those supporting vulnerable populations such as LGBTQ people, young women, and sex workers — said the cuts had disrupted their ability to offer HIV treatments and other services. The Trump administration released limited data showing a deep reduction in HIV prevention services, but a relative consistency in access to treatment earlier this year. However, this new survey paints one of the first pictures available of how PEPFAR cuts are actually being felt on the ground, and how the administration’s priorities are reshaping who and what gets funded.

According to the survey’s authors, at least 1,700 HIV-related sites or clinics have shut down as a result of cuts. Well over 16,000 health workers — including those going door to door to make sure pregnant parents get tested for HIV or children get on treatment — have lost their jobs. 

Many organizations surveyed reported receiving emails when their PEPFAR grants were terminated, noting that their work violated President Donald Trump’s executive order against “unlawful diversity, equity, and inclusion.” It appears, they say, that many of these groups were flagged not because they embraced the distinctly American concept of DEI in their work, but because their name or mission description included a phrase like “gender” or “LGBTQ.”  

A health clinic serving survivors of domestic violence in Mozambique, for example, might now be flagged just for using the phrase “gender-based violence” in their name. This may be part of the reason why even pregnant women — who even the Trump administration has emphasized as a critical demographic in its HIV goals — have lost access to services. 

Back in 2003, Bush defied conservative critics in his own party who attempted to redirect PEPFAR funding to abstinence-only programs. For decades, American presidents have been able to see past their ideology in service of saving lives. They largely understood that contraceptives like condoms and special interventions for those most at risk, including LGBTQ people, were necessary for stopping the spread of HIV. Under the Trump administration, this norm is unraveling. 

“This administration has zero interest in addressing clinical outcomes for vulnerable people with HIV,” said Asia Russell, executive director of the advocacy group Health GAP, who noted that “to be effective, HIV prevention and treatment services actually have to go where the disease is, and that risk is not evenly distributed,” surging in certain geographies like South Africa or within key populations like trans people or young women. Getting support to these groups is “morally right,” she said, but it is also “the only way to do effective HIV work, regardless of your stance on the morals or the merits.”

The fight against HIV is running on fumes

When HIV aid does get doled out these days, it is distributed with far less transparency than in the past, and in ways that often appear to be ideologically or politically driven, both in terms of the populations they serve and the countries they operate in, rather than guided by best practices. 

In theory, lifesaving HIV care was exempted from sweeping aid cuts last year. But in reality, access to even the most basic HIV services and treatments has also atrophied across the board, while falling disproportionately on at-risk populations. 

That’s come both in the form of direct cuts and as a byproduct of broader disruptions to the kind of outreach services, testing, and socioeconomic programs that get patients in the door to begin with. 

“You can’t cut pieces of the architecture of how PEPFAR functions and expect to maintain a really robust treatment program in the long term,” said Jennifer Sherwood, director of research and public policy at amfAR. “If you cut the testing program, the prevention programs, the kind of services that allow people to stay in care and return to care, you’re going to see that you can’t maintain a treatment program.”

The number of people getting on treatment for the first time has sharply declined over the past year, even according to the administration’s own limited data drop, while access to testing, contraceptives, and other preventative services — all critical to keeping infections down in the long run — face cuts that threaten their ability to function at all. 

To make matters worse, amfAR’s survey shows that services designed for the populations most at risk of HIV — such as sex workers, LGBTQ people, young women, and teenage girls — have been disproportionately affected by PEPFAR cuts. Among those who lost funding, a staggering 90 percent of organizations that serve gay and bisexual men were forced to slash access to PrEP — which strongly protects against HIV infection — and many stopped offering it entirely. The same was true for over half of organizations serving pregnant women, whose children now face a higher risk of contracting HIV in the womb.  

The majority of new HIV infections are concentrated in these “key populations,” as they’re known in public health parlance, many of whom face stigma or other obstacles to obtaining care. “One really powerful aspect” of how PEPFAR used to work, said Thomas McHale, public health director at Physicians for Human Rights, was that it consistently “followed the science and followed the epidemiology” to serve “groups that are at the margins of society.” That approach appears to have been thrown out under the new administration, and in at least some cases, actively discouraged.

McHale has been documenting the impact of PEPFAR cuts in South Africa in recent months, and “what we saw was a system under severe stress and strain,” he said. It is one in which a bisexual man stopped taking his HIV medications for weeks because the LGBTQ clinic he used to go to closed. “He just couldn’t bear the stigma of accessing services in a place that’s not meant for him,” according to McHale. Similarly, a young woman was forced to wait in line for 10 hours just to refill her PrEP prescription. 

“If we’re not focusing on preventing disease,” McHale said, “it’s just a more expensive and more devastating challenge to address in the future.”

Some countries may soon stop receiving PEPFAR funding altogether

As I’ve written previously, the Trump administration has attempted to remake foreign aid into a dealmaking enterprise, one in which money flows directly through national governments rather than through large, western-led non-governmental organizations or NGOs. 

In theory, there are benefits to this approach, because it prioritizes the expertise of local health groups and policymakers who are often best equipped to evaluate and address the needs of those in their care. In practice, however, amfAR’s survey shows that so far, under the Trump administration, local organizations have actually lost more funding and been forced to close more sites than international groups have. “These cuts fell heavily on locally-based organizations” while NGOs have fared somewhat better, said Sherwood, “and that really runs counter to all of our global health goals.”  

“I’m concerned because public health is no longer how we’re measuring success” when it comes to reaching PEPFAR’s goals, said Jirair Ratevosian, a senior fellow at the Duke Global Health Institute who served as chief of staff of PEPFAR under the Biden administration. He is especially alarmed by the decision last month to end PEPFAR support for South Africa, which has the largest HIV epidemic in the world. The administration appears to have done so in part because of Trump’s insistence that the nation is waging a nonexistent “genocide” against white Afrikaners. 

“If we’re not focused on preventing disease, it’s just a more expensive and more devastating challenge to address in the future.”

Thomas McHale, Physicians for Human Rights

“HIV control is not their chief concern,” said Ratevosian, who recently ran the numbers on a separate fissure with Zimbabwe, finding that cutting PEPFAR would lead to 75,000 new HIV infections in just one year. In South Africa, similar cuts could lead to over 2 million more infections over the next two decades, a toll that would invariably cross borders, and could threaten the world’s immense, hard-won progress against HIV. “You can’t have a global HIV strategy,” said Ratevosian, “if you’re not engaging these countries.”

Priorities shift under any new administration, and it’s not abnormal for an organization to tweak its language or services to adapt. But PEPFAR, the bipartisan program which began under Republican leadership, and thrived and expanded under three successive presidencies, including during Trump’s first term, has never faced such turmoil. 

“Even among organizations who didn’t lose US funding, we’re still picking up changes to the way they work, the populations they serve, the words they use,” said Sherwood of amfAR. Her group’s survey showed that nearly 80 percent of organizations that did not lose funding still altered the way their organization worked to comply with new policies. “This network of changes from the US,” she said, “are prompting a lot of changes on the ground.”

Gut health is everywhere right now. The hashtag #GutTok has over 6 billion views on TikTok, the global digestive health product market is worth over $60 billion, and viral trends that promise to “hack your gut” through miracle products, cleanses, and restrictive diets are all the rage. But what does gut health really mean, and what can science tell us about how to make sure our gut is in good shape?

The gut microbiome, a complex network of trillions of microorganisms living inside our digestive system, may hold the key to the mysteries of gut health. We have a symbiotic relationship with all of those little guys; we keep them well-fed and they produce substances that can benefit our body and brain. These microbes help regulate bodily functions, protect against disease, and recover from illnesses like cyclosporiasis, which is spreading right now across the US.

But with so many voices chiming in on gut health, pushing everything from probiotic foods and supplements to wellness shots and coffee enemas, it can be hard to tell what information is based on real research and what might just be a marketing gimmick or social media clickbait. Vox spoke to doctors and visited Cedars-Sinai in Los Angeles to bust some gut health myths for science-backed advice. 

Read more about gut health and gut microbiome research:

• Vox editor Katherine Courage’s book, Cultured: How Ancient Foods Can Feed Our Microbiome.
• Cedars-Sinai’s Human Microbiome Research Institute.
• The MAST program at Cedars-Sinai.
• Trisha Pasricha’s book, You’ve Been Pooping All Wrong. 
• Vox’s explainer video on probiotics in yogurt.
• Pew Research Center’s findings on why people look to influencers for health and wellness information.
• The Myths and Scientific Realities About Gut Microbiota.

This video is presented by Colgate. Colgate doesn’t have a say in our editorial decisions, but they make videos like this one possible.

Fermented food is the hottest new trend in the halls of the White House. Members of President Donald Trump’s Cabinet are reportedly walking about with jars of sauerkraut in the hopes that it will give them glowing skin and tiny waists. 

Wall Street Journal’s Liz Essley Whyte told Today, Explained co-host Sean Rameswaram that “Health Secretary Robert F. Kennedy Jr. Commerce Secretary Howard Lutnik, Transportation Secretary Sean Duffy, and Vice President JD Vance are all on this eat-a-lot-of-steak-and-sauerkraut diet.”

So, should we all be eating jars of sauerkraut? Or are ferments just the new Florsheims?

Below is an excerpt of their conversation, edited for length and clarity. There’s much more in the full podcast, so listen to Today, Explained wherever you get your podcasts, including Apple Podcasts, Pandora, and Spotify.

Is there a name for this diet?

Kennedy calls it the carnivore diet. I think people mean different things when they say that, but for him, it includes a lot of yogurt, a lot of kimchi or sauerkraut, a lot of steak, a lot of eggs. Kennedy now travels with sauerkraut. His wife has said that he has asked her to carry it in her purse for him, and she has said, “I actually cannot,” which is an amazing phrase. It seems they all think their skin is glowing, and people online have commented that JD Vance is looking good.

Are we sure it’s not Wegovy?

We don’t have any public knowledge of that, but we do know that he is eating eggs, sauerkraut, pickles, blackberries, and raspberries for lunch pretty often — and beef and lamb with sauerkraut for dinner. Then, when he’s on Air Force Two, he snacks on beef jerky and maybe eats a hamburger with cheese, no bun, and a side of fermented vegetables.

Now that you’re mentioning the full spectrum of JD Vance’s diet, it’s kind of reminding me of their new food pyramid. Is this part of that?

Earlier this year, Kennedy and the other health officials like to say they flipped the food pyramid. They recommended a lot more fruits and vegetables, red meat — which was controversial — and whole grains, and whole milk, that kind of thing. They also, and for the first time in the nation’s dietary guidelines, recommended fermented foods, which was something that was actually agreed upon by a lot of people, and they thought that was a good part of this, even if they had qualms about the red meat recommendations, because those can introduce more cardiac risk and risk of bad cholesterol.

How widespread is this in the White House? Does it go up all the way to the top, to the president?

Given what we have seen of his recent public dieting, I don’t think so. At the Knicks game, he was eating pizza and french fries, and, you know, he still has his Diet Coke button on his desk where he just pushes it and a Diet Coke comes. Kennedy said, once said on a podcast about him, “I don’t know how he’s alive.” 

Does the science back this up, or is this some kind of quackery that ferments can make your skin healthier and help you lose weight?

I don’t think there are a lot of good studies that show exactly that sauerkraut can help you lose weight, but there have been a number of studies that have shown health benefits. Researchers have generally agreed that sauerkraut and other fermented foods can help with digestion and inflammation. There was a 2025 study from UC Davis that suggested fermented cabbage could protect your gut and protect against illness. Basically, they found that the intestinal cells do better with sauerkraut. They help maintain the integrity of those intestinal cells. And, in general, that has a lot of other good health effects. Mainstream scientists, dieticians, are pro-fermented veggies. This is not something that is hotly debated.

Most people in the scientific community are realizing there’s a lot of good fresh science out there about how important your gut really is in your overall health. The part of the diet that is a little more controversial is the focus on red meat. Obviously, that comes with some cardiac risk and some cholesterol risk. That is why when the new dietary guidelines came out and recommended more of that for Americans, that part, in particular, made some dietitians a little upset.

Do you think fermented foods could help people with this parasite that gives you explosive diarrhea?

I personally have not seen any studies on whether fermented foods help with explosive diarrhea, but let me know if you find one.

Update, July 20, 2026, 2 pm ET: This story, first published July 17, has been updated with the current case numbers and developments in the search for the source of the outbreak.

Have you been looking at the lettuce aisle at your grocery store with a wary eye since the diarrhea outbreak began? You’re not alone. This is the summer, which should be high time for fresh produce. But the ongoing emergency has even doctors asking themselves unthinkable questions: Should I stop eating salad? Are any fruits and vegetables safe?

The disease in question, cyclosporiasis, is caused by the parasite cyclospora, which can infect people when it is attached to fresh produce and then consumed. Watery diarrhea — described by public health authorities as “frequent” and “sometimes explosive” — is the most common symptom.

Michigan health officials said last week that they suspect lettuce or bagged salad to be the culprit for the parasite-driven outbreak in the state that has sickened more than 6,100 people. But identifying the specific products to blame has been a challenge. On Thursday, the Washington Post, citing anonymous federal officials, reported the outbreak may trace back to Taylor Farms products that were used by Taco Bell. But then, on Sunday, the FDA said that the tests showing the Taylor Farms product contained cyclospora had been false positives. As of Monday afternoon, the source of the outbreak is still unclear, although Taylor Farms has continued a voluntary recall of its iceberg lettuce products.

I live in Ohio, where there have been nearly 1,200 cases, and I love salad kits. The current outbreak is a major cramp on my lunch plans — and I know I’m not alone. 

So, what do we do? I’ve consulted with a food safety expert and a dietitian to get the answers. The topline message is: Don’t stop eating your fruits and vegetables. They’re good for you. But be smart with your food hygiene.

“I don’t think we’re at that point of shying away from eating your green vegetables,” Francisco Diez-Gonzalez, director of the Center for Food Safety at the University of Georgia, told me. “The benefits overall still outweigh the risks.”

How can we still enjoy our summer produce in this time of cyclospora? Here’s a guide.

Here are the “red light” foods linked to prior outbreaks

While we don’t know for certain the cause of the current outbreak, cyclosporiasis has been linked with specific foods in the past. Let’s start with that list:

• Basil
• Bagged salads and salad mixes
• Cilantro
• Mesclun lettuce
• Parsley
• Raspberries
• Snow peas
• Sweet peas

These foods — either because of where they’re grown or their texture or both — have historically had a higher risk of carrying cyclospora. It might be wise to steer clear entirely for the time being — especially the prepackaged salad products.

The Michigan health department, for example, is urging people to avoid bagged lettuce and salad kits and to purchase whole heads of lettuce instead. And since the outbreak is impacting most states now, it’s advice we’d all be wise to heed.

Then there are “yellow light” foods that need careful cleaning

But for a lot of fruits and vegetables, including whole lettuce, you should still wash them thoroughly — because that’s always a good idea. If you need tips for washing your produce, we’ve got them. For heads of lettuce, for example, cut away the outer layers and wash in between each leaf as best you can. 

“Fresh produce is still generally safe, delicious and nutrient-dense,” Rosemary Trout, a food scientist at Drexel University, told me over email. 

But she gave a yellow light for any leafy greens or fruits and veggies that have textured edible skins. The more texture there is, the more of a risk there is because the parasite can stay attached more easily — even if it’s been diligently washed. Raspberries carry a higher risk than blueberries, for example, and those have been associated with earlier cyclosporiasis outbreaks.

Another point of emphasis: Several doctors have told me that, even if an item says it is prewashed, you should wash it again. And again.

But there are lots of “green light” foods you probably don’t need to worry about

Trout gave a green light to any canned fruits and vegetables, any produce that you cook — importantly, at high heat — at home, and any frozen fruits and veggies.

In general, these are Trout’s safety tips for prepping fruits and vegetables at this uncertain time:

• Be consistent and thorough — at least 20 seconds — when washing your hands and always use hot, soapy water. 
• Peel or remove the outside layer of the fruit or veggies — the rind of a watermelon or cantaloupe, for example, or the outer layer of a head of lettuce.  
• Don’t consume damaged, bruised produce. 
• Keep produce cold in storage, ideally for a relatively short amount of time. 

Get creative with your recipes

If you want to steer clear of any questionable produce or take the safest preparation route that you can, you might want to get a little creative with your recipes. With your lunch salad, for instance, “peeled, shredded carrots, thinly sliced radish, or thinly sliced cooked beets might be a nice substitute for leafy greens,” Trout said.

Heat remains the most surefire way to eliminate any cyclospora parasite that might be lingering on your produce. So look through your cookbooks for any dishes that feature grilled vegetables. Vox Even Better editor Rachel Miller (a more accomplished cook than I) suggested a few recent New York Times Cooking recipes, which you can check out via these gift links:

• Grilled halloumi and vegetables
• One-pan orzo with spinach and feta
• Orzo salad with peppers and feta

Peppers, eggplant, squash, and zucchini are your friends. They respond well to heat, and they are easy to clean. And even some leafy greens — like spinach — hold up nicely to sautéing. 

Support your local farmer’s market

Right now is also a great time to check out your local farmer’s market for produce. 

Dr. Kathleen Linder, who is the hospital epidemiologist at the Veterans Affairs hospital in Ann Arbor, Michigan, told me that she has been buying locally since the outbreak began. Prior outbreaks have been linked to produce that was grown elsewhere — whether in the US or internationally — and shipped long distances before it arrived on our grocery shelves. Summer is a crucial season for small farms and farmers’ markets; they shouldn’t be penalized for a health emergency that they had nothing to do with.

Buying locally could reduce the risk that your produce has been exposed to the parasite. Trout said you can ask your local growers about their water supply to make sure that what you are buying is safe.

“Single-source produce from a local farm with good manufacturing/farming practices in place, with a safe water supply, are good,” Trout told me. “Commercially processed, pre-packaged foods are likely combining produce from various farms, which may increase risk, despite good manufacturing practices in place.”

So while cyclosporiasis is an unwelcome concern as we plan our summer cookouts, it doesn’t need to stop you from enjoying fresh fruits and vegetables. Be a little more diligent about your food hygiene, get a little creative with what you’re preparing, maybe stop by a farmer’s market — and you’ll be fine.