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On the Friday after Thanksgiving, Vinay Prasad, the FDA’s top vaccine regulator, made a claim that shocked the public-health establishment. “For the first time,” he wrote in a leaked email to his staff, “the US FDA will acknowledge that COVID-19 vaccines have killed American children.” The agency had supposedly identified at least 10 children who died from getting COVID shots.

To say the email was poorly received by vaccine experts and physicians would be an understatement. Prasad’s claim provoked a rapid series of rebuttals. A response from 12 former FDA commissioners, published in The New England Journal of Medicine on Wednesday, called Prasad’s memo “a threat to evidence-based vaccine policy and public health security.” All of the potential vaccine-related deaths reported to the government, presumably including those to which Prasad referred, had already been reviewed by the agency’s staff, the former commissioners wrote, and “different conclusions” had been reached. Elsewhere, doctors and scientists declared that absolutely no evidence links COVID-19 vaccines to death in children; and that in order to suggest otherwise, Prasad and his colleagues had engaged in an “evidence-manufacturing mission,” a “dumpster dive” for shoddy data, or—worse—a campaign of lying.

Prasad is among the public-health officials who, under the leadership of Robert F. Kennedy Jr., have been systematically undermining the nation’s confidence in immunizations. Prasad has not yet offered up any documentation to support his assertion, and his count of vaccine-related deaths may well turn out to be inflated. The memo’s overheated rhetoric and lengthy recitation of political grievances also raise some doubts about his claims.

Yet there’s something troubling—and telling—in the fact that his memo has provoked people to deny even the possibility of COVID-vaccine-related deaths. The idea that mRNA-based shots have, tragically, killed a very small number of children is not far-fetched. It also doesn’t imply a catastrophic threat to public health, given that tens of millions of doses of these vaccines have safely been given out to young people. From the start of the coronavirus pandemic, lack of nuance has been a problem with public-health messaging—one that anti-vaccine advocates have made use of to great effect. Now, in a moment when public health in America is under existential threat, this insistence that no evidence exists for vaccine-related deaths risks adding to the crisis.

No public-health authorities deny that COVID shots can have some ill effects. Adverse reactions are possible with all medical interventions. The mRNA-based vaccines produced by Pfizer and Moderna, in particular, are known to cause myocarditis—inflammation of the heart—on rare occasions, especially in teenage boys and young men. The form of myocarditis that occurs after vaccination is typically far less severe than the one caused by viruses; for unclear reasons, mRNA-related cases have largely disappeared in recent years. But this condition can be deadly, and considering the hundreds of millions of mRNA doses that have been administered to Americans, even extraordinarily unlikely outcomes may well be inevitable.

[Read: ‘It feels like the CDC is over’]

In August 2021, U.S. physicians published details of a 42-year-old man’s post-vaccination death from myocarditis in The New England Journal of Medicine. Similar cases trickled in from other countries too. South Korean researchers and public-health officials, who tracked postimmunization fatalities very closely, identified a total of 21 deaths from vaccine-induced myocarditis—all in adults—during their country’s initial COVID-inoculation campaign, which reached more than 44 million people. And in 2022, one of my former instructors, the forensic pathologist James Gill, Connecticut’s chief medical examiner, found that children could also be at risk of death. Writing in a peer-reviewed journal, he and his colleagues described the cases of two teenage boys who died of heart damage after receiving their second Pfizer dose.

So why is Prasad’s allegation that a very small number of kids have died from COVID shots being treated as some unholy aberration? I reached out to Paul Offit, a former member of the CDC’s immunization advisory committee who had described the memo’s assertions as being “fairly fantastic.” He told me that although Prasad’s claim may ultimately pan out, he does not consider the published case reports definitive, nor does he believe that the shots have led to any deaths. “It’s not terribly convincing that this vaccine killed anybody,” he said.

Michael Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, gave the same response: He doesn’t think that the COVID shots have yet been linked to any deaths, and he trusts the judgment of the officials who had first reviewed these cases. (Like Offit, he allowed for the possibility that such cases might be identified in the future.)

When I reached out to Krutika Kuppalli, an infectious-disease physician who works on vaccine safety, she told me that high-quality studies from around the world have clearly demonstrated that there isn’t any wave of mRNA-related deaths. Population-level data show no increase in mortality from the Pfizer or Moderna COVID shots. This means that if the immunizations do cause death, it happens so infrequently as to be statistically undetectable. (Abundant evidence shows that the vaccines reduce mortality from SARS-CoV-2. That statistical signal is clear as day.)

[Read: Revenge of the COVID contrarians]

But there’s a disconnect among the sort of studies cited by Kuppalli and doctors’ observations on the ground. The latter may get written up in case reports of vaccine-related deaths, and although any single finding from this literature can be debatable, that doesn’t mean it ought to be ignored. Cause-of-death determinations happen every day in medicine, based on the most likely explanation of the facts. Yet when vaccines might be involved, that standard seems to change: Suddenly, authorities demand an impossibly high level of evidence.

Experts told me that any of the published cases of death from an mRNA vaccine could have resulted from some alternative cause, such as a preexisting condition or hidden infection. True enough, but these cases were thoroughly investigated. Many of the diagnoses were confirmed by autopsy, which is considered the gold-standard diagnostic approach. The 21 Korean deaths, in particular, were verified by a panel of specialists in cardiology, infectious disease, and epidemiology. Surely these, at least, should meet the bar for establishing a person’s cause of death—but the doctors and public-health professionals I spoke with for this story insisted that such reports don’t amount to slam-dunk proof. “These are important for hypothesis generation and mechanistic understanding,” Kuppalli said, “but they do not establish causality for death.”

Many mainstream experts have been drawing from the same playbook that COVID skeptics used at the height of the pandemic. Five years ago, they and others asked: Were thousands of American children truly getting hospitalized for COVID, or did they get hospitalized for some other reason and just happened to have COVID? Now we get a similar question: Did the teenagers who died after getting their Pfizer shots die from COVID vaccination, or did they just happen to die from something else after having been vaccinated?

The CDC itself has at times adopted this turbocharged incredulity. After Gill’s team published about the two teens, who died after receiving mRNA vaccines in the spring or summer of 2021, Tom Shimabukuro, then a high-level official in the CDC’s Immunization Safety Office, and several other agency staffers wrote a scathing letter to the journal, claiming that important facts had been omitted. They said the agency had found laboratory evidence of infection—a virus in one case and a bacterium in the other—and that at least the latter “suggested an alternate cause of death” that should have been mentioned in the paper.

[Read: Mortality numbers may have more to do with politics than science]

The CDC’s critique, however, was premised on errors so rudimentary that any trained pathologist should be able to spot them: The PCR test used to detect the virus in one case is known to be unreliable for determining a true infection, for example; the bacteria implicated in the other typically grow only after a patient is deceased. Given the flimsy reasoning behind the CDC’s rebuttal, Gill’s cases could easily be among the 10 deaths that the FDA is now touting. Yet according to a June 2025 presentation by the director of the CDC’s Immunization Safety Office, “no known deaths or cardiac transplants” were seen in individuals ages 12 to 29 with post-vaccine myocarditis from January to November 2021. Another slide said there was “no increased risk of death following mRNA COVID-19 vaccines.” (Neither the Department of Health and Human Services nor Shimabukuro responded to questions about this story.)

Some defensiveness about the data on vaccine-related harms is understandable. Anti-vaccine activists, the HHS secretary among them, have spent years stoking unfounded fears about mRNA vaccines; doing so has almost certainly resulted in otherwise preventable deaths among those who refused to get vaccinated. And it may well be that this administration’s claims about the harms from COVID shots are unfounded, and that no persuasive evidence will ever be provided. (The FDA has indicated that supporting data will be released later this month.) But given what is already known, the public-health establishment should be prepared for the alternative. Accepting and acknowledging reasonable proof of that reality would be an important part of effectively combating the government’s current vaccine skepticism. How can medical professionals discuss the favorable risk-benefit profile of these shots if they aren’t willing to acknowledge their worst risk? Denial also creates opportunities for those who want to break the system to rebuild it. In his memo, Prasad presents a very small number of allegedly catastrophic events as a revelation of such grave importance that “swift action” must be taken in regard to the COVID vaccines and the immunization approval process overall.

The possibility—perhaps the likelihood—that a handful of vaccine-related deaths occurred and were downplayed by medical authorities does not undermine the fact that COVID vaccination, on the whole, has prevented death on a massive scale. Nor does it justify sweeping changes to vaccine regulations. Rather, it suggests the need for some targeted reforms, such as improvements to the country’s vaccine-adverse-event reporting system—and also tells us that a strategy of minimizing tragic outcomes, however rare, may not be the best way to protect a vital instrument of public health.

Updated at 11:35 a.m. ET on December 8, 2025

For a decade after its discovery, CRISPR gene editing was stuck on the cusp of transforming medicine. Then, in 2023, scientists started using it on sickle-cell disease, and Victoria Gray, a  patient who lived with constant pain—like lightning inside her body, she has said—got the first-ever FDA-approved CRISPR gene-editing treatment. Her symptoms vanished; so did virtually everyone else’s in the clinical trial she was a part of.

This year, the technology has started to press beyond its next barrier. Most of the 8 million people globally who have sickle-cell disease share the same genetic mutation; treating rare disorders will require dealing with many different mutations, even within the same disease. And although rare diseases affect 30 million Americans in total, relatively few people are diagnosed with each one. Fyodor Urnov, a scientific director of UC Berkeley’s Innovative Genomics Institute (IGI), showed me a list of rare diseases and pointed to one carried by only 50 people. “Who’s going to work on a disease with 50 patients?” he asked. And even within one disorder, each person might need their own customized CRISPR treatment. Drug developers have little financial incentive to spend years and millions of dollars designing therapies that may need to be tailored to literally one person.

The technology is ready to treat at least some of these diseases, though. “There’s a whole toolbox now that can target arguably any part of the genome pretty precisely,” Krishanu Saha, a gene-editing researcher at the University of Wisconsin at Madison, told me. If researchers could build one CRISPR platform for a single disease, or even several similar ones, and tweak that template to suit each patient, they could target extremely rare disorders more quickly and economically. Maybe the first patient’s treatment for a disease takes $2 million and a year of development; by the third patient, the cost should be down to, say, $100,000 and a month of development, Urnov said, because you’ve already proved that the reused components are safe.

“We have been moving in the direction of thinking about CRISPR as a platform for some years,” Jennifer Doudna, the IGI’s founder, who shares the Nobel Prize for discovering CRISPR gene editing, told me. But, in her mind, 2025 was the first time many people understood its potential. A baby named KJ Muldoon is a big reason why.

In February, Muldoon became the first child to receive one of these customized CRISPR gene-editing treatments, tailored to fix his specific mutation. People born with his rare genetic disease, a type of urea-cycle disorder, have about a 50 percent chance of living past infancy. If they do, they live with extreme developmental delays and usually require a liver transplant. But when he was six months old, Muldoon got his bespoke treatment, and now he’s a healthy 1-year-old. His therapy was proof that custom gene-editing treatments can work and that they can be spun up relatively quickly, yet safely.

His treatment also gives scientists a chance to try the platform approach. The next child treated for a urea-cycle disorder should now be able to receive a CRISPR treatment from Muldoon’s template, tweaked to their unique DNA. CRISPR technology uses guide RNA, a molecular GPS of sorts, to send an editor protein to a particular address in someone’s DNA. Targeting a different mutation just means changing the address. Muldoon’s case put more momentum, too, behind personalized gene editing in general. The federal government recently announced two major  programs that offer funding to scientists working on personalized treatments for rare diseases. The focus now, Doudna said, is figuring out how to make customized CRISPR “available to anyone who needs it.”

For years, one of the main roadblocks has been the U.S. drug-regulatory system. Its approval processes were designed for traditional drugs that help many people, not a bespoke treatment that helps one child in Philadelphia. The FDA has considered each treatment, even for the same disease, as a different drug. Biochemically, two therapies might be the equivalent of a pizza with pepperoni and another with artichokes. But under the FDA approval process, “you go back to square one. You recertify the oven. You recertify the person who throws the disk of dough. You confirm the cheese is still safe to eat,” Urnov, who was also part of the team that designed Muldoon’s treatment, said. The FDA has been trying to change that process over the past few years, and last month, two of its top officials, Marty Makary and Vinay Prasad, announced a new drug pathway that could speed up approvals for personalized rare-disease treatments. The framework was inspired in large part by the success of Muldoon’s therapy. (The FDA did not respond to a request for comment.)

The new pathway opens the door to the platform approach that scientists have hoped to take. If researchers could prove they’d successfully treated a small number of patients for one rare genetic disease, they could continue customizing treatments for other mutations, and potentially also for similar conditions. That streamlined process could finally attract for-profit players—the best shot at actually getting these customized therapies to patients en masse, Doudna said. “If we’re able to bundle trials together so that we’re able to treat multiple related diseases without starting from scratch, that could completely change the economics of treating rare disease,” she said.

The first clinical trials in this model will begin soon. Urnov and his colleagues plan to investigate a platform for rare immune disorders; Rebecca Ahrens-Nicklas and Kiran Musunuru, the geneticists who treated Muldoon at the Children’s Hospital of Philadelphia, told me they are planning to start one this winter for children with various types of urea-cycle disorder. If all goes according to plan, another child should receive a treatment based on Muldoon’s in the near future.

Working this way does put more responsibility on scientists to test their therapies thoroughly, Ahrens-Nicklas said. Gene editing can go wrong: A treatment may accidentally alter the wrong part of a patient’s DNA, or the delivery mechanism could trigger a deadly immune reaction in their body. “If you have to treat fewer subjects in order to get that approval, you want to make sure that you’re really robustly measuring the safety on those few subjects” and communicating any risks to the wider gene-editing community, she said. But done well, these trials are a major step toward getting more custom treatments out to more people.

All of the researchers I spoke with emphasized that these are early days. Because of how the current gene-editing delivery mechanisms work, scientists are mostly limited to treating disorders in the blood and liver. And researchers are focused on single diseases, or groups of similar ones, for now. Their dream would be to have a CRISPR platform that could address many disparate disorders, but the current reality is that many, many families will still go without bespoke therapies. Muldoon’s treatment “took a team of people at both nonprofits and for-profit companies in multiple countries working at a scale I have never seen before,” Doudna said. And they changed his life. His parents weren’t sure if he’d ever be able to sit upright on his own, but recently, Muldoon took his first steps. The press has dubbed him a “miracle baby.” Now miracles like his need to become commonplace.

This article originally misstated the full name of the Children’s Hospital of Philadelphia.

Updated at 4:33 p.m. ET on December 5, 2025

In case there was any doubt before, it’s now undeniable that Robert F. Kennedy Jr.’s allies are in charge of the country’s vaccine policy. The latest evidence: His handpicked vaccine advisory committee voted today to scrap the decades-old guidance that all babies receive the hepatitis-B vaccine shortly after birth. Now the panel recommends that only children born to mothers who test positive for the infection or have unknown status automatically receive a shot at birth. Everyone else has the option of a shot at birth or—as the committee recommends—waiting until at least two months after birth.

Those who favor the change argue that other countries, such as Denmark and Finland, vaccinate only newborns of mothers who test positive, and that rates of infection are relatively low in the United States. All of this is true. But in the U.S., many expectant mothers don’t get tested for hepatitis B, and even if they do, those tests sometimes fail to pick up the virus. The rationale for giving the vaccine right away is to wipe out an infection that will afflict the majority of people who contract it as babies for the rest of their life (and, for as many as a quarter of those chronically infected, result in their death from cirrhosis or liver cancer). The World Health Organization and the American Academy of Pediatrics both endorse the universal birth dose. “When you remove that foundation, you essentially cause the whole prevention process to collapse,” Noele Nelson, a former CDC researcher who has published multiple papers on hepatitis B, told me.

The meeting, which began yesterday, was also proof that Kennedy, and those he’s empowered, no longer feel bound by previous norms. In June, Kennedy fired every outside adviser on the committee, alleging unspecified conflicts of interests (even though members are required to disclose those conflicts and recuse themselves when necessary). He has since stacked the board with members who share his doubts about vaccine safety. During the previous meeting, in September, those new members seemed at times unaware of basic facts about vaccines and often unsure about what they were voting on. In the end, their recommendations were fairly modest, advising that children younger than 4 receive two separate shots for MMR and chickenpox.

This week’s meeting was, if anything, more chaotic. Days before it started, Martin Kulldorff, a former Harvard Medical School professor who had been chair of the advisory board, left the committee for a position at the Department of Health and Human Services. The new chair is Kirk Milhoan, a pediatric cardiologist who is a member of the Independent Medical Alliance, a group that has promoted the use of ivermectin to treat COVID-19 despite clinical trials showing that the drug isn’t effective against the virus. But Milhoan didn’t show up in person for the meeting, leaving the moderating duties to Vice Chair Robert Malone, the author of the conspiracy-theory-driven book PsyWar and a hero to people who oppose COVID vaccination; Malone has called Anthony Fauci “an accomplice to mass murder.” (HHS did not respond to a request for comment, nor did Malone or Milhoan.) In the days leading up to the decision on the hepatitis-B shot, committee members received four different versions of the question they’d be voting on, and the final language is still difficult to decipher.

[Read: The most extreme voice on RFK Jr.’s new vaccine committee]

The meeting was dominated by presentations not from career CDC staff, as it was even in September, but from fringe figures who are closely aligned with Kennedy. Mark Blaxill—a longtime Kennedy ally in the anti-vaccine cause who now works for the CDC—gave a presentation about hepatitis-B-vaccine safety. He noted that he’d been “a critic of the CDC for many years, so it’s been an honor and a privilege to work on the inside and to address some of these issues.” Another presenter, Cynthia Nevison, is a research associate at the University of Colorado at Boulder’s Institute of Arctic and Alpine Research. She is also one of Blaxill’s co-authors on a 2021 paper on rising autism rates that was retracted after the journal’s editors and publisher concluded that they had made a host of errors, including misrepresenting data. (Blaxill told me that the paper was later published with “modest additions” in another journal.)

Just as the meeting was more chaotic than earlier iterations, the pushback was even sharper. Cody Meissner, a pediatrician and committee member who’d also served on the board during the Obama administration, noted, accurately, that rates of hepatitis B have declined in the United States “thanks to the effectiveness of our current immunization program.” Malone interjected—as he did at several points in the meeting—that this was merely Meissner’s opinion. “These are facts, Robert,” Meissner responded. Joseph Hibbeln, a fellow committee member, shouted that there hadn’t been “any information or science presented” about whether delaying the hepatitis-B dose by two months made sense. Amy Middleman, a pediatrician and representative of the Society for Adolescent Health and Medicine, urged the committee “to go back to our true experts” at the CDC. Adam Langer, a longtime CDC expert who is the acting principal deputy director of the center that oversees hepatitis prevention, at one point cautioned the committee not to use countries such as Denmark, which has a much smaller population and more comprehensive prenatal care, as a basis for comparison. Most panelists seem not to have cared.

In the end, the concerns of the committee’s few dissenters—along with the chorus of objections from representatives of medical organizations—were disregarded. The committee voted overwhelmingly (8–3) to change the recommendation. “This has a great potential to cause harm, and I simply hope that the committee will accept its responsibility when this harm is caused,” Hibbeln said afterward. The board also voted that parents should have the option of testing their children’s antibody titers against hepatitis B before they receive subsequent doses of the vaccine—a move for which, several meeting participants pointed out, there is little scientific support. A senior CDC scientist wrote to me that it was the “least science-based, most illogical public health recommendation in U.S. history.” The committee’s decisions are not final yet: The CDC director still needs to sign off on them. Because Kennedy pushed out Susan Monarez less than a month after she was confirmed as director, the decision will rest with the acting director, Jim O’Neill, whom Kennedy selected as deputy HHS secretary and who has no background in medicine.

[Read: ‘It feels like the CDC is over’]

The new normal for the vaccine advisory committee appears to be the appearance of vigorous scientific debate in which the experts are either not consulted or simply disregarded. That doesn’t bode well, because the committee apparently plans to reconsider the rest of the childhood-immunization schedule—something Kennedy promised Senator Bill Cassidy, who chairs the Senate health committee, that he would not do. Earlier today, the committee heard a presentation from Aaron Siri, a lawyer who worked for Kennedy’s presidential campaign and has represented clients who believe that their children were injured by vaccines. He used his time to spell out his doubts about the childhood-vaccine schedule.

According to Malone, the committee had asked Paul Offit and Peter Hotez, both widely respected vaccine experts, to appear as well. In an email, Hotez told me he declined because the board “appears to have shifted away from science and evidence-based medicine.” Offit told me in an email that he didn’t remember being asked to attend but that he would have declined because the committee “is now an illegitimate process run by anti-vaccine activists.” Even Cassidy, who has mostly stopped short of directly criticizing Kennedy’s actions in office, slammed Siri’s appearance in front of the committee, posting on X earlier this week that the committee was now “totally discredited.” (When I asked Siri for comment, he pointed me to an X post in which he’d challenged Cassidy to a public debate on vaccines. A spokesperson for Cassidy’s office did not respond to a request for comment.)

At the end of today’s meeting, the board gave a preview of its next target: aluminum salts, which are used in a number of childhood inoculations to boost immune response. (A presentation on the topic by Kulldorff was originally scheduled for today, but was removed from the agenda last night.) A recent study of more than 1 million Danish children found no evidence that aluminum salts are associated with neurodevelopmental disorders such as autism. Yet Milhoan, the new chair, said concerns had “reached a threshold where it needs to be considered.” Another member, Retsef Levi, speculated about how new safety trials might be conducted. If the committee decides at its next meeting, in February, that a common ingredient, used in vaccines for decades, is unsafe, it could upend childhood immunization in the United States. Which is, of course, exactly what many of Kennedy’s longtime allies have wanted all along.

Throughout the 2000s, the music charts were rife with references to Rogaine. Jay-Z invoked the hair-restoration drug as a synonym for staying power. Weezer described it, begrudgingly, as a means of rejuvenation. Ingrid Michaelson, in a song about accepting one’s flaws, pledged to buy the drug for her partner when he inevitably lost his hair.

Now, as the Millennials who grew up on this music are fast approaching their Rogaine era, the hair-loss industry is eager to receive them—particularly the many women coming around to the idea that they might want to buy Rogaine for themselves too. Over roughly the past decade, hair-loss treatments aimed at women have broken into mainstream consumer culture, alerting women simultaneously to the possibility of balding and the potential to fix it.

Women have always been the target audience for shampoos, hair masks, hot-oil treatments, and so on. But those products aim to improve the appearance of existing hair, not grow more of it. Products specifically for hair loss have historically targeted male users. When Rogaine launched in 1988, it was available only for men. (The women’s version came three years later.)

Advertising for hair loss has, accordingly, mostly focused on men. Throughout the big-hair craze of the 1980s and ’90s, infomercials for men’s spray-on hair were all over TV. In a Rogaine ad from 2001, a narrator asks: “Will she feel the same way if you lose your hair?” (The answer: “Sure, she’ll just feel it about somebody else.”) Hair-growth treatments are an easy sell for men because many will go bald in midlife. Yet 40 percent of women experience some amount of hair loss by the time they turn 50. They just haven’t been as comfortable talking about it as men, Rachael Gibson, a hair-culture expert known online as the Hair Historian, told me.

Now brands and their ambassadors have taken the microphone. Nutrafol, a women-focused hair-supplement company that launched in 2016, has started selling its products at Sephora and Ulta. My Instagram feed is full of female influencers holding up fistfuls of loose hair and presenting sparsely populated scalps—then hawking serums, supplements, and shampoos that supposedly restored their voluminous mane. (Before watching these videos, I had no suspicions that my hair was falling out; afterward, I was convinced that with the right products, I could look absolutely equine.) When Hers launched in 2018, it offered topical minoxidil, the generic form of Rogaine. Over the past three years or so, many providers (including Hers) have started prescribing oral minoxidil, a hypertension drug, off-label to treat hair loss, which can be a welcome alternative to sticky topical versions. Hers and its men’s counterpart, Hims, also sell some of their hair-loss products at Walmart.

The proliferation of women’s hair-restoration products is impossible to separate from the booming menopause market. As pop-culture depictions of menopause have become more prominent over the past few years, numerous drugs, supplements, and telehealth platforms have sprung up to address it. Shoshana Marmon, a dermatology professor at New York Medical College, told me that she has observed a growing number of influencers targeting women in midlife, when hair usually starts to thin. Midi Health, a menopause-focused telehealth platform, started offering oral and topical minoxidil in 2023, and it screens patients for common issues, such as iron deficiency and thyroid problems, that can drive hair loss, Kathleen Jordan, Midi Health’s chief medical officer, told me. And because fluctuating hormones during menopause are a major driver of hair loss in women, hormone-replacement therapy can sometimes help.

Of course, hair-loss companies are ready to sell these products to anyone, not just aging women. In beauty chains and drugstores, numerous oral hair-loss supplements containing ingredients such as biotin and vitamin A are displayed alongside shampoos and conditioners. Last year, products for thinning hair and scalp health were among the fastest-growing categories in the roughly $450 billion prestige-hair-product market, according to the market-research firm Circana. Widespread hair loss during the coronavirus pandemic may have juiced demand for hair-loss products, and the rise of direct-to-consumer telehealth companies likely accelerated the trend: Hair-loss treatment is popular at Hims and Hers, a company spokesperson told me, because many people find hair loss embarrassing and telehealth allows them to seek help discreetly.

[Read: The year America’s hair fell out]

The most commonly prescribed hair-loss drugs are well established and generally trustworthy. Minoxidil is the “gold standard” of active ingredients for hair loss, Paradi Mirmirani, a dermatologist with Kaiser Permanente, told me. In both topical and oral forms, it works by slowing or reversing hair-follicle shrinkage, which tends to happen as hormones fluctuate. A drug called finasteride is sometimes used to reduce shedding; Midi Health combines it with minoxidil and two less-used hair-loss drugs in a “Regrowth Serum.” But finasteride is most commonly prescribed to men; it isn’t FDA-approved for women for hair loss, because it can be dangerous to pregnant women and their fetuses. (It has also been linked to panic attacks and suicidal thoughts in some men.)

Meanwhile, hair-loss supplements, like all supplements, are somewhat of a tangle. The highest-quality evidence available offers some support for swallowing ingredients such as zinc, pumpkin-seed oil, and omega-3 and omega-6 fatty acids, Elizabeth Houshmand, a fellow with the American Academy of Dermatology, told me. But purity, dosing, and consistency vary widely among products, and their safety and effectiveness aren’t regulated by the FDA. Herbal supplements that lower DHT, a hormone that shrinks the hair follicle, can sometimes be beneficial, but medications are “the only thing that really does work,” Spencer Kobren, the founder of the American Hair Loss Association, a consumer-advocacy group, told me.

The predominantly male focus of the hair-loss industry, combined with women’s reticence about thinning hair, has left many women clueless about the possibility that they, too, may lose their hair. “We hear all the time from our consumers that ‘I didn’t know,’” Cindy Gustafson, the CEO of Nutrafol, told me. Some are too embarrassed to bring it up with their provider, fearing that their concern will be criticized as vain or, worse, dismissed as just a part of life, Jordan said. Unlike men, who are generally more aware of hair-loss drugs and use them as a first line of treatment, women tend to rely on trusted friends and hairstylists for advice, Kobren said, noting that they usually try four to six non-pharmaceutical hair-loss products before consulting a doctor. Unfortunately, he added, women also tend to spend the most on hair-regrowth snake oil.

[Read: Soon there will be unlimited hair]

Women today are in an unprecedented position: They’re receiving more messages than ever about the possibility of balding, even as they’re bombarded with products to fix it. Perhaps this shift will make women more comfortable taking their hair concerns to their doctor, rather than to friends and influencers. But it seems equally likely to change nothing. Like smooth skin and mental clarity, perfect hair suddenly seems within reach at any age—as long as you’re willing to pay.

“Ozempic is about to be old news,” my colleague Yasmin Tayag wrote in 2023, just before an even more powerful obesity drug, tirzepatide, then best known as Mounjaro, was approved. Well, two years later, Mounjaro is becoming old news, too. A whole slew of next-generation obesity drugs are on the horizon, some already advanced enough in clinical trials to be looking as good as—if not better than—those already on the market. The novel medications continue to push the upward limits of weight loss, now to almost 25 percent of body weight on average, but they also differ in their modes of action. They target different cells and different parts of cells in the brain and body.

Obesity, after all, is not monolithic. “We don’t have a disease of obesity. We have a disease of obesities,” Angela Fitch, chief medical officer at Knownwell, a national obesity-care clinic, and a former president of the Obesity Medicine Association, told me. With the coming explosion of obesity drugs, doctors could soon match each patient’s condition to their optimal medication: A 25-year-old with fatty-liver disease may need a different drug than a 75-year-old with low muscle mass. About 100 million adults live with obesity in just the U.S., a market massive enough for multiple mediations to find a niche. “One size will not fit all, and one size will not be best for all,” Richard DiMarchi, a chemist at Indiana University who has worked on obesity drugs at both Eli Lilly and Novo Nordisk, told me.

The most obvious way obesity drugs are not one-size-fits-all is that those on the market do not actually work for all. Although patients on semaglutide, the drug in Ozempic and Wegovy, lost on average 10 percent of their body weight, a third lost less than 5 percent in one clinical trial. Some even gain weight taking the drug. And others suffer such terrible side effects, including constant nausea and vomiting, that they cannot take it at all.

Ozempic functions by mimicking a single hormone called GLP-1; the drug’s mode of action is relatively simple but limited. To improve upon Ozempic, drugmakers have started targeting GLP-1 in combination with other hormones linked to hunger and satiety. The second drug currently on the market, the tirzepatide found in Mounjaro and Zepbound, resembles GLP-1 in addition to another hormone called GIP, hitting receptors for both in the brain. The GIP component may serve a double function, promoting additional satiety while suppressing some of the nausea caused by GLP-1. However tirzepatide truly works—and experts caution that no one knows—it prompts, on average, about 20 percent weight loss. It’s only the first of the “GLP-1 plus” drugs to market.

Other GLP-1-plus drugs in development include GLP-1 plus amylin, GLP-1 plus glucagon, and GLP-1 plus anti-GIP, which surprisingly could work as well as Mounjaro’s combination of GLP-1 plus GIP. (“If you aren’t confused,” Randy Seeley, an obesity researcher at the University of Michigan, told me, “you aren’t paying attention.”) In fact, all of these combinations seem to work—at least based on preliminary data from clinical trials—even as a precise understanding of the science lags. Some of the hormone mimics, such as for amylin, might also work alone. And others could be remixed into combinations of more than two. The drug retatrutide, which is in trials, is a triple hitter that targets GLP-1 plus glucagon plus GIP receptors, all at once. In an early Phase 2 trial, patients lost on average 24 percent of their weight, the highest of any obesity drug so far. The best responders lost upwards of 40 percent.

Even more intriguing than the top-line weight-loss numbers are metabolic changes unique to particular drugs. Glucagon, for example, ramps up liver metabolism; drugs based on this hormone could help break down fat accumulated in the livers of patients who also have fatty-liver disease. (The FDA is expediting review of one such drug, survodutide, for liver-disease patients.) Meanwhile, GLP-1-based drugs appear to protect against cardiovascular disease, even independent of weight loss. Patients prone to heart disease might fare best on medication that includes a GLP-1 component. When it comes to obesity, Seeley said, “your flavor of metabolic disease will be different than the next person’s.” Obesity drugs of the future may finally reflect that diversity, too.

An extensive menu of obesity drugs that work via distinct biological mechanisms means that patients will have more options to try. If they aren’t losing weight on drug A, they can move on to drug B or C. Experts don’t yet understand why the drugs work differently in different people, but hormone receptors in our brains likely vary in subtle yet important ways. The new drugs not only hit distinct combinations of hormone receptors; they also each tickle those receptors in a unique way.

In the near future, doctors and patients will probably have to trial-and-error their way to what works best. Further down the line, experts tell me, they hope to have a test, such as a blood test, that can forecast how patients will fare. Doctors could tell patients that they’ve got five different drugs at the ready, “and if I do this one test on you, I do this one test on you, I can predict which one of these drugs is the best for you,” Jonathan Campbell, an obesity researcher at Duke University, told me.

Maximum weight loss might not always be the goal for everyone though. The 40 percent that some people lose on retatrutide would be far too much for a patient barely over the BMI cutoff for obesity. Patients who don’t need to optimize weight loss may choose to prioritize convenience instead, which drugmakers are also happy to oblige. Most obesity drugs on the market are formulated as weekly injections. But Eli Lilly is developing a daily pill called orforglipron, and Amgen is testing a monthly injection called MariTide. And some patients, especially those who are elderly with already low muscle mass, might need extra help preserving their strength. The powerful appetite suppression that induces fat loss can induce muscle loss too. A number of drugmakers are now trialing obesity drugs in combination with various muscle-preserving drugs.

A mere decade ago, obesity drugs powerful enough for people to routinely drop double-digit percentages of their body weight were unheard-of. Today, there are two, and they feel ubiquitous. In yet another 10 years, this toolbox of just two obesity drugs will likely appear tiny and outdated. The next phase of the obesity-drug revolution is coming, with more drugs to choose from.

There’s a fairy tale about Thanksgiving that gets refuted every fall. Does eating turkey really make you fall asleep? When science writers check in with the experts, they always get the same response: No, no, no, and no. Also no and no.

These holiday debunkers tell you what the science says: Turkey meat is not a sedative. They tell you what the studies show: Drumsticks don’t produce fatigue. And then they take another step, however ill-advised: They lay out different reasons Thanksgiving dinner might be sleep inducing. Even as these stories bust the turkey-coma myth, they end up replacing it with other fables.

The trouble began nearly half a century ago. It started with warm milk—a sleep aid that was the subject of its own lightly flavored brand of science journalism. Was it true that a mug of milk could help you go to sleep? Yes, the experts said, because milk has tryptophan! This one amino acid worked something like a natural “sleeping pill,” a psychiatry professor told The New York Times in 1983. “Once again,” the Times said, “an old wives’ tale, the one about warm milk before bedtime, has received scientific support.”

Indeed, a tryptophanic fever was about to spread across America. By the end of the decade, tryptophan was being widely sold in supplements as a treatment for insomnia; an aid for beating jet leg; and also a fix for depression, PMS, and drug dependence. (Tryptophan was even talked about as a suicide preventive.) To explain its wondrous potency, scientists noted that when tryptophan made its way into the brain, it could be converted into the neurotransmitter serotonin. According to the thinking of the time, serotonin was the molecule of relaxation and well-being. Early studies seemed to show that it led to sleep.

Turkey, too, contains some tryptophan. Thus the sleepy-turkey myth was born. But even from the start, experts knew the theory had some complications. In the first place—as every Thanksgiving-myth-debunking article notes—turkey doesn’t have a lot of tryptophan. In fact, almost every other kind of meat has more. One serving of turkey breast contains 244 milligrams of tryptophan; one serving of clams contains 243. You’ll get less tryptophan from turkey, ounce for ounce, than you will from octopus or cheddar cheese. And in the second place, even taking high-dose tryptophan supplements doesn’t seem to do so much for sleep. (In 2017, the American Academy of Sleep Medicine recommended against the use of tryptophan as a treatment for insomnia on account of its “absence of demonstrated efficacy.”)

If only that could be the end of it. The early experts on the topic had laid out some other dietary theories of ensleepification. Tryptophan was soporific, the MIT neuroendocrinologist Richard Wurtman and his colleagues said, but its effects were limited by the degree to which it crossed the blood-brain barrier. Other nutrients from foods could get in its way. But Wurtman, who died in 2022, found that when you ingest a bunch of carbohydrates, the resulting spike of insulin can shunt away the amino acids that normally compete with tryptophan. As he saw it, carbs have a “sedating effect” in the human diet, by helping tryptophan to make its way from the gut into the brain. If it seemed as though a mug of warm, protein-rich milk was helping people get to sleep, that’s because they must also have been eating cake.

Wurtman was already floating this idea—let’s call it the sleepy-carbs hypothesis—in the early 1980s, and it has been repeated in the press ever since. Almost all articles about the turkey-coma myth now point at carbohydrate-heavy side dishes, the sweet potatoes and the pie, and claim that these Thanksgiving foods, not the turkey, really knock you out.

This merely swaps one highly suspect notion for another. Studies find that meals with lots of carbohydrates don’t really make you sleepy. (They may have some small effects on how you sleep, such as an increase in the time you spend in REM, the dreaming phase.) More to the point, the old idea that serotonin is a simple, sleep-promoting signal in the brain is fully out of fashion; later research found that serotonin may also be a potent source of wakefulness, and that its function in the sleep-wake cycle is both complicated and diverse.

Nutritionists may now be more inclined to look at melatonin, a hormone that is synthesized (like serotonin) from dietary tryptophan. One line of research looks at whether sour cherries or beefsteak tomatoes might be useful as a sleep aid, because these foods are known to be rich in naturally occurring melatonin. When taken as a supplement, melatonin seems to have a small effect on sleep onset and sleep quality; when taken as a tomato, it may also have some benefits. That said, the American Academy of Sleep Medicine recommends against the use of melatonin as a treatment for insomnia for a similar reason that it recommends against tryptophan: insufficient evidence of clinically meaningful results.

In short, all the science here is pretty weak. Yet the turkey-myth debunkers pile on the speculations. The sleepy-carbs hypothesis is just the start. What accounts for post-Thanksgiving lethargy? Many experts blame the fact that we’re consuming so much food, and overeating makes you tired on its own. (Some even cite the old-fashioned and unlikely notion that heavy digestion deprives your brain of oxygen.) But the evidence that people are more inclined to fall asleep, for any reason, after pigging out—that they experience what’s known among the cognoscenti as “postprandial somnolence”—is equivocal, at best.

This is science—and this is science journalism—of the sort that only makes you dumber the more of it you read. Here are some other reasons you might feel tired after eating dinner on Thanksgiving: You have consumed some alcoholic beverages; you have traveled a long distance; you have gotten trapped in some exhausting conversation with your cousin’s wife. Also maybe this: Dinner time is over, and the sky is dark, and a lot of time has passed since the last time you were sleeping.

And allow me to lay out one final possibility: What if Thanksgiving dinner doesn’t even make you sleepy in the first place? Could the very basis for the turkey-coma myth, and for all of its debunkings, be a sham? I could find no data to suggest that the Thanksgiving-meal effect is real. “Nobody’s tested this,” Faris Zuraikat, a nutrition and sleep scientist at Columbia University, told me when I called him for this story. So here we are today, dressing up a folk belief about the holiday with pseudoscientific rationales. It’s a pointless and exhausting project. We should be thankful if it ends.

Photographs by Elinor Carucci

Robert F. Kennedy Jr. somehow knew, even as a little boy, that fate can lead a person to terrible places. “I always had the feeling that we were all involved in some great crusade,” Kennedy once wrote, “that the world was a battleground for good and evil, and that our lives would be consumed in that conflict.” He was 9 years old when his uncle was assassinated and 14 when his father suffered the same fate. I happened to be sitting next to him this fall when he learned that his friend Charlie Kirk had been shot. We were on an Air National Guard C-40C Clipper en route from Chicago to Washington, D.C., and one of Kennedy’s advisers, her eyes filling with tears, whispered the news in his ear. “Oh my God,” he said.

National Guard stewards handed out reheated chicken quesadillas, which Kennedy declined in favor of the quart of plain, organic, grass-fed yogurt his body man had secured for him. A few weeks earlier, a man who believed that he’d been poisoned by a COVID vaccine had fired nearly 200 bullets at the CDC’s campus in Atlanta, hitting six buildings and killing a police officer. Kennedy, who as secretary of Health and Human Services oversees the CDC, had just told me that his security team recently circulated a memo warning him of threats to his own life. “It said the resentments against me had elevated ‘above the threshold of lethality,’ ” he said. Kennedy greeted the threat assessment with remarkable equanimity. He put down his spoon in order to finish his yogurt in gulps directly from the container.

In an atmosphere of rising distrust of U.S. institutions, where even once-untouchable bastions of expertise such as the scientific establishment had been badly weakened by the coronavirus pandemic, Kennedy had emerged as a Rorschach test—truth-telling crusader, or brain-wormed loon?—for how Americans understood the populist furies riling the country. I’d told him that I wanted to understand his journey from liberal Democrat and environmental activist to MAGA insider and Kennedy-family heretic, on the theory that by examining his odyssey, I might better understand what separates us and help narrow the political divide. He was sympathetic but skeptical. “Yeah, if you pull that off …,” he said, trailing off with a laugh.

Kennedy himself has done much to fuel the rising distrust. He views some of the world’s most celebrated scientific and political leaders as charlatans. He calls some of the experts who work under him at HHS “biostitutes,” because he considers their integrity for sale to the industries they regulate. He rejects much of the scientific consensus regarding vaccines, arguing that they have likely seeded the growing epidemic of chronic illnesses. During a Senate Finance Committee hearing just days before our flight from Chicago, Kennedy had called one U.S. senator a liar and another ridiculous. A bipartisan majority of the panel, including two Republican doctors, voiced concerns that vaccine policies he supported threatened the lives of American children. Kennedy argues that journalists like me are complicit, along with the public-health establishment, in hiding truth from the American people. The nation was tearing itself apart, and Kennedy had positioned himself at the seams.

“The whole medical establishment has huge stakes and equities that I’m now threatening,” he told me. “And I’m shocked President Trump lets me do it.”

A year earlier, Kirk, the founder of the conservative youth group Turning Point USA, had hosted an event with Kennedy the same day the candidate ended his quixotic presidential campaign and endorsed Donald Trump. JFK and RFK Sr. “are looking down right now and they are very, very proud,” Trump had said on the occasion. Now, as we flew over Ohio, no one knew if Kirk would live. At the front of the plane, aides to Attorney General Pam Bondi, who was also on board, were using the in-flight Wi-Fi to stream the gruesome videos of the shooting on social media. Kennedy’s adviser came back with a draft post for the secretary’s X account: “Praying for you, Charlie.”

“Say ‘We love you, Charlie.’ ” Kennedy instructed.

Three days later, Kennedy had just returned from a Saturday-morning 12-step meeting for addiction near his new house in Georgetown—a neighborhood that the extended Kennedy clan had long called home but that he now described as a “liberal enclave”—when he texted me saying that he wanted to continue our conversation about the country’s social breakdown.

A majority of the people in his recovery meeting, he said, “were probably horrified the first time I walked in, because, you know, they read The New York Times and they watch CNN, and so I’m kind of like a monster to them,” he said. “Over time, I became very welcome.”

This gave him hope that, outside the rooms of recovery, we could shrink our divisions. Parts of society, he said, are supposed to function independent of politics. Science is one of them. “The entire purpose of science is to search for existential truths,” he said. “It’s not subjective. It should be objective. I believe science is a place where you can find unity if you can get a conversation going.”

The problem is that the conversation had long since broken down. In 1900, the top three causes of death in the United States were pneumonia, tuberculosis, and diarrheal diseases, which collectively killed nearly 1 percent of the country every year. A staggering 30 percent of all deaths occurred in children younger than 5. By the end of the century, vaccinations, antibiotics, clean water, improved sewage treatment, and pest control had drastically reduced the lethality of infectious diseases. Today, young children account for less than 1 percent of U.S. deaths. Life expectancy has been extended by nearly 30 years. This is a monumental accomplishment, attributable to the efforts of scientists and lawmakers who tested hypotheses, built consensus to pass policies, and then corrected that consensus when new evidence arose.

But since about 2010, the long, steady increase in life expectancy has flatlined. Chronic illnesses such as heart disease, cancer, stroke, and lung disease now top our mortality tables—affecting some 130 million Americans and accounting for 90 percent of our $4.9 trillion annual health-care expenditure. We are the world’s least healthy high-income nation, bombarded with prescription-drug ads and buffeted by a wellness industry of alternative fixes. A September poll by Navigator, a Democratic public-opinion firm, found that seven in 10 Americans are convinced that the health system “is designed so drug and insurance companies make more money when Americans are sick.”

Kennedy aims to channel the frustrations of that majority to remake public health. He arrived at this goal by way of his decades as a trial lawyer focused on contamination of the nation’s water by polluting corporations. In the latter part of his career, he has come to perceive a comparable contamination of American health by pharmaceutical and food companies. A central premise of Kennedy’s leadership at HHS is that modern science is infected with bias that costs lives—that the regulatory agencies have been captured by industry, that medical journals are corrupted by the need to turn a profit, that even respected organizations such as the American Academy of Pediatrics operate with a myopic groupthink that hurts kids.

For years, Kennedy was a gadfly outsider. The scientific establishment ignored him. Even now that he sits atop America’s health bureaucracy, Kennedy told me, public-health authorities—whose convictions, he said, are more akin to religion than science—will not engage with him. He blamed his opponents for dodging his arguments on vaccines. “Why for 15 years have they refused to have a conversation with me? I’ve been asking for 15 years for somebody to come up and debate me on this,” he told me. “Their reaction to that is ‘Oh, don’t debate him. He’s too crazy. You don’t want to give him a platform.’ ”

In 2017, Kennedy thought he’d finally gotten the audience that would allow him to make his case about vaccines. At Trump’s insistence, Kennedy and some allies, including Aaron Siri, a vaccine-safety litigator, came to the National Institutes of Health with a stack of 84 studies that they said supported their claims about the unrecognized dangers of vaccines.

“We tried to engage him. We were trying to debate him,” Joshua Gordon, the former director of the National Institute of Mental Health, told me. He and his colleagues attended the meeting to argue that existing studies demonstrated no connection between vaccines and conditions such as autism, and to explain why Kennedy’s papers “were suspect.” But, Gordon said, “Kennedy and Siri refused to engage.”

Kennedy and Siri insist that it was the doctors and scientists who refused to engage, and Siri has published emails showing that Gordon eventually ended the conversation by referring them to the CDC. The meeting solidified Kennedy’s conviction that he was dealing with a cult unwilling to look at evidence that challenged its worldview.

Today, a similar pattern is playing out between Kennedy and his own staff. In late August, Kennedy asked that Trump fire Kennedy’s handpicked CDC director, just four weeks after she’d been confirmed by the Senate, because Kennedy was convinced that she was aligning herself with her agency’s scientific staff and against him. He replaced the members of the CDC’s vaccine advisory committee because he’d concluded that their COVID-era decision making had been unscientific and industry-influenced. His team uses social media to attack science reporters by name.

Even some members of Kennedy’s newly adopted party are alarmed. Last February, Senator Bill Cassidy of Louisiana, a gastroenterologist and the Republican chair of the Senate Health, Education, Labor, and Pensions Committee, cast the deciding vote to confirm Kennedy as HHS secretary. A liver specialist, Cassidy has treated patients with cirrhosis caused by having been born with hepatitis B, a condition that can be avoided with newborn vaccination. Though Cassidy has thus far declined to renounce his endorsement of Kennedy, he rejects the secretary’s suggestion that the hepatitis vaccine might be dangerous when given to newborns.

“I’ve invited Bill Cassidy and others to sit down with me and go through the studies and let’s figure out which ones are right,” Kennedy told me. “That has to happen through real debate and conversation, and there’s no real place to have that in the current political milieu.”

When I conveyed Kennedy’s frustrations to Cassidy, the senator said that he and the HHS secretary regularly share scientific articles and papers with each other. “I find that he often will send me the same article more than once,” Cassidy told me. Yet whenever Cassidy points out “statistical flaws” in the article, he said, Kennedy says he considers those “immaterial.”

I had been having a similar experience. As I reported this article, Kennedy referred me to many studies meant to convince me there are not two valid sides to this debate, that his is the only valid one. I’m not a scientist. I’ve admittedly been inconsistent in getting my yearly COVID and flu boosters, confused about their benefits. Now the most powerful public-health official in the U.S. was asking me, a political reporter, to referee a medical debate with life-and-death stakes.

I called Paul Offit, a pediatrician and the director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, and one of the most outspoken critics of Kennedy’s vaccine views. Offit helped invent a rotavirus vaccine that has mitigated a major cause of early-childhood hospitalization around the world. Kennedy routinely attacks him as a paragon of financial conflict because the owners of the vaccine patent, including his hospital, gave him some of the proceeds from its sale. The accusation relies entirely on circumstantial evidence: Offit’s early rotavirus research was funded by the National Institutes of Health, not private industry; he advocates for vaccination and sells books about the benefits of vaccines, but nothing suggests that he has ever done anything untoward in pursuit of profit. Like many of the people I spoke with for this article, Offit has faced death threats from radicals who believe his vaccine advocacy is deadly. Some have targeted his children.

Offit told me that Kennedy is a “liar” and a “terrible human being.” I asked him to explain. “It doesn’t matter what I say,” Offit said. “He thinks the medical journals are in the pocket of the industry, he thinks that the government is in the pocket of the industry, he thinks I’m in the pocket of industry, and he’s wrong.” Offit continued: “If he has data showing he’s right, then fucking publish it. He can’t, because he doesn’t have those data.”

I asked Offit if he saw a way to reverse the public’s rising distrust in science. “I don’t think there is any way to regain that trust other than have the viruses do the education, and the bacteria do the education, and then people will realize they paid way too high a cost,” he said.

From 2011 to 2024, the percentage of kindergarten students whose families asked for nonmedical exemptions to vaccine mandates doubled, to more than 3 percent, according to the CDC. Florida just announced an end to school vaccine mandates, and Idaho passed a law banning them. Cassidy’s office has been monitoring rising rates of pertussis, a bacterial infection also known as whooping cough; symptomatic infection is avoidable with a vaccine. Cassidy’s working hypothesis is that declining vaccination rates in red states will show up in the data. Kennedy counters that existing data are not specific enough to show whether the new infections are among the unvaccinated.

I first interviewed Kennedy for this story in June, in his office on the sixth floor of HHS headquarters, a brutalist gray block of concrete that resembles a giant air-conditioning unit. Kennedy’s staff jokes that the building feels like a prison; the secretary pointed out the great view he would have of the U.S. Capitol’s dome, if not for the building’s deep-set windows.

Kennedy is 71, but with the help of weight lifting, artificial tanning, a careful diet, and testosterone-replacement therapy, he looks more like a comic-book character than a senior citizen, his bronzed face all chiseled angles, his eyes sky blue. He adheres to a strict uniform at work—dark, embroidered skinny ties like his father sometimes wore, with suit jackets that bulge over his bodybuilder’s chest and biceps. He regularly pulls Zyn nicotine pouches from his shirt pocket or desk drawers to tuck between his lower lip and gum. When I asked him to square his nicotine habit and the time he spends tanning with the federal health advisories against both, he shifted in his chair. “I’m not telling people that they should do anything that I do,” he said. “I just say ‘Get in shape.’ ”

Kennedy told me his staff believed that speaking with me was a mistake. For the first half century of his life, national magazines hailed him as a public servant, a potential heir to the Kennedy kingdom—even, as Time magazine put it in 1999, a “Hero for the Planet.” “The Kennedy Who Matters,” New York magazine declared in 1995, saluting RFK Jr.’s environmental advocacy. In 2006, Vanity Fair posed him on the cover of its “green issue” with George Clooney and Julia Roberts.

But the favorable coverage dried up about 20 years ago, when he began arguing that mercury additives in vaccines were likely causing an epidemic of autism. This claim was contradicted even at the time by epidemiological studies by the CDC and others. Editors who did not want to discourage lifesaving vaccination stopped running flattering articles and started running critical ones. “All-out hit pieces,” he told me, “every one of them—like, ugly, hateful stuff.” For 20 years now, he said, only “bad articles” have been written about him.

Yet in the aftermath of COVID, his popularity has surged. Like Trump, Kennedy has drafted on the currents of populist backlash against expert authority. “When I’m on the street, I get stopped three times a block by people saying that they love me,” he said. Kennedy is among the most popular members of Trump’s Cabinet, according to an August Gallup survey: 42 percent of the country holds a favorable view of him, on par with the president himself. The public attacks on Kennedy’s character and integrity bother him, naturally, but he wanted me to know that I was not a threat. “If he screws us on this,” he recounted telling his staff, “it’s just another shitty article in a liberal paper, which doesn’t really hurt me.”

He believed that I’d screwed him before, anyway. I’d first met him in the spring of 2023, when he was challenging President Joe Biden for the Democratic Party’s nomination. The Washington Post story I wrote focused on his argument that the powerful were lying to the American people—about vaccines, environmental threats, the assassinations of his father and uncle, and much else. He hated the story largely because I’d used the word conspiratorial in the headline, which he argued was an elitist epithet for tinfoil hat. I placed him in the tradition of what the political scientist Richard Hofstadter described as America’s paranoid style, while acknowledging that secret conspiracies of the powerful—tobacco companies, the intelligence community—sometimes do exist.

He responded by sending me an email nearly twice the length of my original article, with 78 footnotes. (At the time, he was suing the Post for its role in a consortium designed to combat misinformation online.) “Your reporting on me reflects, exquisitely, the overt aspirations by your employer and its co-conspirators to crush nonconformist viewpoints in order to secure their own economic self-interests,” he wrote. Weeks later, on a podcast, he accused me of being “part of a conspiracy, a true conspiracy.”

I had never received an email like that from a politician. If I was hopelessly corrupt, why spend hours writing a response? It struck me that Kennedy believed himself to be on a ferocious quest. “There is nothing that is a show about what you are seeing,” Mike Papantonio, a former legal partner of Kennedy’s who co-hosted a program with him on the liberal radio network Air America in the mid-aughts, told me. “That is real rage.”

Kennedy and I stayed in touch. In October 2023, getting little traction from Democratic-primary voters, he relaunched his presidential campaign as an independent. Despite not having a clear path to even a single electoral vote, he didn’t stop until August 2024, when he endorsed Trump, a man he had weeks earlier publicly described as appealing to “some of the darkest impulses in the national psyche.”

As we talked more recently in his wood-paneled HHS office, he leaned back in his chair behind an oversize desk, with one of his five book-length attacks on the federal medical establishment, The Real Anthony Fauci: Bill Gates, Big Pharma, and the Global War on Democracy and Public Health, displayed nearby. From that seat, he oversees one out of every four dollars in the federal budget and regulates about 17 percent of the nation’s economy. How, I asked him, did he explain going from scorned activist to the boss of the public-health apparatus?

“I would say in one word: providential,” Kennedy said.

If I were to do this story right, Kennedy told me, I needed to talk with his top deputies: Jay Bhattacharya, the director of the NIH; Marty Makary, the commissioner of the FDA; and Mehmet Oz, the cardiothoracic surgeon turned TV doctor known for having hyped dubious “miracle” cures, who is now running the Centers for Medicare and Medicaid Services. All three of these physicians, like Kennedy, say that they were transformed by the pandemic, which they thought public-health authorities had mishandled. They had dissented from government edicts regarding vaccine mandates and masking. Although they do not embrace all of Kennedy’s views on vaccines, his deputies share his big-picture view that America’s public-health system is broken.

Early in the pandemic, Bhattacharya, a Stanford University physician and health economist, co-wrote the 2020 “Great Barrington Declaration,” a document that argued against universal COVID lockdowns in favor of allowing healthy people to gather while isolating only those groups at greatest risk of severe illness or death, such as the elderly and the infirm. For this, Bhattacharya was ostracized by colleagues at Stanford and the broader scientific community: An email that later became public shows Francis Collins, then the NIH director, telling colleagues that they needed a “quick and devastating published take down” of the declaration. (Tens of thousands of Americans a month were dying from COVID at that time; overstrained hospitals were at risk of collapse.) Death threats—a recurring feature of public-health work these days—followed for Bhattacharya, who now compares the COVID years to pre-Enlightenment Europe, when Galileo Galilei was imprisoned by Catholic leaders for arguing that the Earth orbited the sun.

“What you had is a relatively small number of scientists who could decide what is true or false for all of science and all of society,” Bhattacharya told me. Today, even some of those who led the public-health response during those years admit that COVID-vaccine mandates may have been counterproductive, that social distancing lasted too long, and that masking may not have done much to limit transmission—though it is also true that we cannot know now how much higher the death rate would have been without those measures in place.

The COVID vaccines led to a substantial reduction in hospitalization and death from the disease, according to peer-reviewed studies. But Kennedy likes to emphasize that, as the virus evolved, the vaccines failed to prevent infection, as scientific authorities had initially suggested they would. Kennedy also dismisses the mathematical modeling of the lives saved, and says CDC estimates of the COVID death toll were inflated by “data chaos” in the government. What no one doubts is that the severity of the pandemic—more than 95,000 Americans were reported dead in one month at its height—has transformed the nation’s relationship with medical authority. From 2020 to 2022, public confidence in the CDC dropped from 82 to 56 percent, according to a study by researchers at the University of Texas Southwestern Medical Center. The country has still not recovered.

Kennedy’s team blames its Biden-era government predecessors. When I met with Makary, who worked as a pancreatic surgeon before being named FDA commissioner, he said that, in times of uncertainty, a dangerous and self-defeating “groupthink” can take over. Kennedy and his allies point to how public-health authorities urged social-media platforms to curb the posting of COVID misinformation, stifling debate. Kennedy himself got kicked off Instagram. In one social-media post, he called the death of the baseball great Hank Aaron at age 86 “part of a wave of suspicious deaths among elderly closely following” COVID-vaccine shots. Critics accused Kennedy of speculating baselessly about Aaron’s cause of death, and quoted the medical examiner’s office saying Aaron had died of natural causes. Kennedy, in turn, accused his critics of ruling out a vaccine connection without a proper autopsy, and demanded that one be done.

The COVID experience bonded Kennedy, Makary, Bhattacharya, and Oz in a fellowship of the ostracized. “We became renegades, personae non gratae, because we asked questions which you would think, certainly within academic medicine, you should be able to ask,” Oz told me in his office, where he keeps a taxidermic honey badger to symbolize fearlessness and aggression.

After Trump’s reelection, Kennedy’s HHS-leadership-team-in-waiting gathered at Oz’s 10-bedroom, 18,559-square-foot Palm Beach house, not far from Trump’s Mar-a-Lago estate. The house was built by the same architect who built the mansion down the beach where Kennedy had spent vacations during his childhood. “It has the same smell to it,” he said. In the mornings, Kennedy would call on anyone who was around to go swimming in the ocean or throw a football with him, before his team settled down to plan the future of U.S. medicine. Kennedy’s friend Russell Brand—a comedian, an actor, and a fellow recovering addict who has pleaded not guilty to rape and sexual-assault charges in England—would sometimes join them. Kennedy says that those months in Palm Beach validated his decision to walk further away from the Democratic Party and most of his own family, who remained prominent Trump opponents. The Republicans hanging around Oz’s house, Kennedy told me, “were all very idealistic people, which was not my view of the Republican Party growing up. To me the most breathtaking and refreshing part of being down there is that people were not sitting in rooms, as the Democrats imagine, thinking, How do we cut taxes for rich people and screw the poor? They were saying, ‘How do you make every American better?’ ”

At one point, leaders of Stanford visited, only to be grilled by Kennedy and Oz about why the university had opened an investigation into Bhattacharya’s professional conduct during the pandemic. The outcasts had become the authorities.

Kennedy now compares his relationship with the president to “when you’re dating somebody that you keep liking more and more.” They began meeting after the failed assassination attempt on Trump in July 2024. Kennedy came to believe that his previous impressions of Trump—that he was a “bombastic narcissist” who lacked curiosity and didn’t read books—had been wrong. “One day he sat on the plane with me. We were talking about Syria, and he drew a map of the Mideast for me. And it was a perfect map,” Kennedy told me. “Then he drew in the troop strength of each country, and also the troop strength on various borders.” Trump would recite sports trivia to Kennedy, and recount the net worth of major Wall Street financiers.

“I had to start seeing Trump as a populist who is standing up to really entrenched power and the deep state and that merger of state and corporate power,” Kennedy told me. He acknowledges that this makes Trump a strange “paradox”—“because he’s the most business-friendly guy at least since George W. Bush.”

That’s saying something coming from Kennedy, who in the early 2000s compared Bush’s pro-corporate environmental policies to the work of European fascists. I asked how he reconciled his criticism of Bush with working in the Cabinet of a president who appointed an oil executive, Chris Wright—who recently called Al Gore’s climate-change warnings “nonsense”—as energy secretary. “Chris Wright has a diverse worldview,” Kennedy told me.

For decades, RFK Jr. continued to call himself an “FDR/Kennedy liberal.” The embrace of MAGA has lost Kennedy friends and strained his family. At a rally against vaccine mandates in 2022, Kennedy described the U.S. COVID response as totalitarian, and warned that new technologies would give the government greater power to control Americans than the Nazis had over Anne Frank in Europe. In response, his sister Kerry Kennedy posted on X, “Bobby’s lies and fear-mongering yesterday were both sickening and destructive.” When RFK Jr.’s own wife, Cheryl Hines, famous for playing Larry David’s wife on the HBO show Curb Your Enthusiasm, publicly criticized him for those remarks, he apologized. Kennedy and Sheldon Whitehouse, a Democratic senator from Rhode Island, were once such close friends that they were in each other’s weddings. Now, when Whitehouse questions Kennedy at public hearings, his voice drips with disdain. “You have my cellphone,” Kennedy told his former friend during their last Finance Committee confrontation, in September. “I’ve never heard from you in seven months. Call me up. I’d love to meet with you.” (Kennedy says Whitehouse replied to his offer in late October and said he would meet, after Whitehouse’s Senate office had declined a request for comment from The Atlantic.) More recently, his cousin Tatiana Schlossberg, one of JFK’s granddaughters, who has terminal cancer, wrote in The New Yorker that she “watched from my hospital bed as Bobby, in the face of logic and common sense,” became HHS secretary, and admonished him for cutting cancer-research funding. (Kennedy declined to comment.)

“To stay on course despite that jeering really tells you a lot about his messianic self-regard,” the New York Democratic politician Mark Green, another former friend of Kennedy’s, told me recently. “He is sadly off his rocker to argue that Biden was more anti-speech and fascist than Donald Trump.”

Over time, Kennedy and his team united around an organizing theory of their department. “It’s a $1.73 trillion bundle of perverse incentives,” he told me. “The doctors, the hospitals, the insurance companies, the other providers, the pharmaceutical companies are all incentivized to make money by keeping people sick.” Fixing this would require radical measures.

The ensuing year has been a whirlwind of controversy, destruction, and new initiatives. Kennedy and the Trump White House pushed out, through firings and induced retirements, about one in four HHS employees, including much of the senior career staff and thousands of workers at the CDC, which Kennedy described to me as a “snake pit.” Early on, working with Elon Musk’s team at the Department of Government Efficiency, Kennedy canceled hundreds of millions of dollars in research grants, and defended a White House budget proposal that cut 40 percent of the NIH’s funding, even while saying that he would accept more money if Congress decided differently. “I talked to Elon a lot about this,” Kennedy told me. “You have to do something disruptive at the beginning.” If you don’t, “you lose momentum.”

On May 27, he shook scientists at the CDC by announcing that his department would no longer recommend COVID boosters for healthy children or pregnant women, on the grounds that clinical trials had not sufficiently demonstrated safety and efficacy for those populations. The career staff was outraged; Kennedy presented no new data on potential harm that would have compelled rescinding the existing recommendation, and it is well established that COVID infection increases the danger to both mother and fetus. “I knew that those decisions were going to harm people,” Lakshmi Panagiotakopoulos, a top adviser on COVID vaccines for the CDC, who resigned in response to Kennedy’s new policy, told me. “From my perspective as a scientist and someone who has done this her entire career, he has a lot of blood on his hands.”

Days later, Kennedy removed the 17 members of the CDC committee responsible for recommending vaccination schedules and replaced them with a smaller group that promptly ordered the removal of a mercury preservative, thimerosal, from flu vaccines, even though the CDC continues to describe thimerosal as “very safe.” Kennedy’s new committee put up barriers against a single shot to vaccinate children for measles, mumps, rubella, and varicella, citing past studies by Merck and the CDC that found a higher incidence of febrile seizures following the combined vaccine. Kennedy also canceled $500 million in federal grants for mRNA-vaccine research, citing his conclusions, disputed by medical associations, that the technology performs poorly against fast-mutating respiratory viruses.

In other areas, he’s pushed for changes that health activists and wellness influencers on the left, as well as many in the scientific mainstream, have long sought. He launched initiatives to review baby-formula ingredients, issue new guidelines for fluoride use, limit student cellphone use, stop the sale of illegal flavored vapes, and remove restrictions on whole-milk sales at schools, and he persuaded governors in 12 states to ban the use of food stamps to buy sugary sodas. He announced plans to explore limits on direct pharmaceutical advertising and the marketing of unhealthy food to children, increase nutrition education for doctors, reduce prices on some drugs, add front-of-package labeling on ultra-processed foods, and require more testing of food additives. Under pressure from Kennedy’s HHS, major food producers announced that they would remove certain petroleum-based food dyes from cereals and candy.

Kennedy’s deputies describe him as endlessly curious about new science, and willing to listen to dissenting views. Bhattacharya told me that, during the 2025 measles outbreak in Texas, the worst in decades in the U.S., he privately advised Kennedy to endorse the measles vaccine as the most effective way to prevent the disease. “When you give him the evidence, he changes his mind along the lines of what the evidence says,” Bhattacharya said. Kennedy did go on to call the measles vaccine effective—while also emphasizing that parents should make their own decisions and promoting disputed treatments such as cod-liver oil for measles symptoms.

The secretary also consumes scientific studies by the bushel. In August, Andrea Baccarelli, the dean of the Harvard T. H. Chan School of Public Health, published a review of the existing science suggesting a possible connection between taking Tylenol during pregnancy and the development of autism or attention deficit disorder in children. Kennedy told me he spent a weekend reading 70 studies related to this. He spoke with Baccarelli, started texting directly with another researcher on the topic, and asked the CEO of Kenvue, the company that now owns the Tylenol brand, to bring scientists to HHS to brief him.

Kennedy arrived at a rather nuanced set of conclusions—more nuanced than what his boss would subsequently express. High fevers in pregnant women are known to cause bad outcomes in newborns. So any public-health advice recommending against Tylenol, which reduces fevers, would have to be carefully weighed, he told me. But when he briefed Trump on his findings, Kennedy said, the president’s response was to suggest immediately posting a Tylenol warning on social media.

“You can’t do that,” Kennedy said he told the president. “There’s nuance to it, and you can’t scare people away from Tylenol, and you’re going to get a huge amount of pushback from powerful pharmaceutical companies.” Trump’s reply: “I don’t give a shit about that.” The FDA-advisory note that Marty Makary released to accompany the announcement weeks later asked doctors to exercise caution in using the medication for low-grade fevers but said that there was as yet no proof of a causal link between Tylenol and developmental disorders.

Trump, however, has less patience for nuance. “Don’t take Tylenol. Don’t take it,” the president said at a press conference on September 22. “Fight like hell not to take it.” The medical community responded with outrage. The American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, and other prominent health organizations put out statements advising doctors and patients to disregard Trump’s recommendation.

Through all this, Kennedy has praised the president’s fearlessness and compassion. A few months earlier, at a White House event, RFK Jr. compared Trump to President Kennedy, who had worked with the biologist Rachel Carson in the early 1960s to reduce the use of pesticides. “My uncle tried to do this, but he was killed and it never got done,” Kennedy said, sitting alongside Trump. “And ever since then, we’ve been waiting for a president who would stand up and speak on behalf of the health of the American people.”

In a family steeped in its own mythology, RFK Jr. was always particularly susceptible to the pathos and grandeur of the Camelot mystique. His father encouraged him to read heroic poems like Alfred, Lord Tennyson’s “Ulysses,” and as a child Bobby Jr. memorized Rudyard Kipling’s “If—” and “Gunga Din.”

The legend of King Arthur resonated with a boy who was more interested in catching salamanders and snakes in the forest than in schoolwork. T. H. White’s novel The Once and Future King, which tells the story of young Arthur’s tutelage under Merlyn, was a particular favorite. “That was how I got interested in falconry,” Kennedy told me. When he was 11, his father gave him his first red-tailed hawk. Kennedy named the bird Morgan le Fay, after Arthur’s sorcerer half sister.

But when his father was murdered, Ethel Kennedy, Bobby Jr.’s mother, was left to care for 11 children in a world churning with youthful rebellion. One day in the summer of 1969, Kennedy remembers, he attended a farewell party on Cape Cod for a young soldier heading off to Vietnam. He said LSD had arrived from California that summer, and while he was hitchhiking home that night, someone offered him a dose. His favorite comic book at the time, Turok, Son of Stone, followed the exploits of Native Americans who lived among prehistoric animals. In one of the comic’s storylines, the Native Americans consume a hallucinogenic fruit. “Will I see dinosaurs?” Kennedy told me he asked the person offering him the LSD. “I had a deep interest in paleontology,” he explained to me. That was perhaps the first time this particular reason has ever been given for deciding to take psychedelics.

A picture of his dead father and uncle behind the counter of a local diner as the drug wore off spoiled his trip. At which point another group of kids offered him a line of crystal meth. The initial rush was strong enough to set him on a new life path. Within months, he was traveling to New York City to buy $2 heroin on 72nd Street. “I had been administering drugs and giving shots to animals since I was a kid. And so it wasn’t a hard jump for me,” he said, about using needles to inject himself with drugs. “There were other kids in my town who were shooting speed.” He was 15.

In January 2025, after Trump announced that he would be nominating Kennedy as HHS secretary, his cousin Caroline Kennedy, JFK’s daughter, wrote a public letter opposing his confirmation, in part because of what she’d witnessed during his years as a young drug user; she blamed him for leading others in the family “down the path of addiction.” She described young Bobby as a “predator” like the raptors he’d raised, saying he had grown “addicted to attention and power.” “His basement, his garage, and his dorm room were the centers of the action where drugs were available, and he enjoyed showing off how he put baby chickens and mice in the blender to feed his hawks,” she wrote. “It was often a perverse scene of despair and violence.”

When I read Kennedy those words, he barely reacted. “I would not contest it that much,” he said. “Addiction is kind of narcissistic.”

By the time he was accepted into Harvard (his father, his uncles, and his grandfather had all gone there), he had been pushed out of multiple boarding schools, been arrested for marijuana possession, and become estranged from his mother. When he was still a teenager, he hopped trains to Haight-Ashbury, in San Francisco, to hang with the hippies, and worked in a Colorado lumber camp. His heroin addiction would last 14 years, continuing during his time as a law student at the University of Virginia, as well as through his first marriage, to Emily Black, a fellow UVA law student, whom he married in 1982. In September 1983, he overdosed on a flight to South Dakota. He was charged with heroin possession, for which he was sentenced to two years’ probation, and spent the next five months in a rehab facility in New Jersey. Shortly after he left treatment, his brother David Kennedy, younger by about a year, died of a drug overdose in a Palm Beach hotel room while other family members were gathered at the Kennedy estate nearby.

Although Kennedy says he has not taken heroin since he got clean, he still considers his brain to be a sort of “formulation pharmacy,” able to transform anything—rock climbing, falconry, sex—into a drug. In 2024, New York magazine parted ways with its reporter Olivia Nuzzi after learning of what it deemed was an inappropriate personal relationship with Kennedy, whom she’d profiled the previous year. (After the print edition of this article went to press, more detailed allegations about his relationship with Nuzzi emerged. Kennedy declined to comment.) A former babysitter for Kennedy’s children told Vanity Fair that he had groped her when she was 23 and he was 45. Kennedy apologized to the babysitter in a text message after the article’s publication, though he said he did not remember the incidents she described. “I am not a church boy,” he said publicly. “I have so many skeletons in my closet that if they could all vote, I could run for king of the world.”

After his time in rehab in the early 1980s, Kennedy says he remade himself through the routines and principles of Alcoholics Anonymous—a combination of spiritual devotion, radical transparency, and a focus on service. As a presidential candidate, he told his security detail that he had to attend a 12-step meeting every day, no matter where he traveled. He has continued that practice since moving to Washington from Los Angeles. I asked him how much being an addict in recovery still affects him. “I think it’s shaped everything,” he said. Even as HHS secretary, he sponsors others in recovery. “I take calls all the time.”

In his own view, recovery from heroin addiction has returned him from damnation to walk again among the living. “Having kind of lived through hell,” he told me, paraphrasing something he said he’d read while he was still using, gives you a different perspective on life, and the opportunity for “a kind of redemption.” To rebuild his self-esteem, he worked to replace the secret shame of his addiction with a life dedicated to a purpose bigger than himself. In this way, his private recovery, anchored in his Catholic faith, fused with his public crusade against what he believes are grave threats to American health. But this is also, perhaps, what gives his jeremiads about vaccines and other matters such fervor. “You’ve got to, you know, completely commit yourself to a way of life,” he said, talking about the 12-step process. “It’s Joseph Campbell’s hero’s journey that we are all on.”

After entering recovery, he built up Riverkeeper, a nonprofit dedicated to protecting the Hudson River and other New York watersheds; founded an environmental-law practice; divorced Black; got married a second time, to Mary Richardson, an architect; and began a lifelong battle against chemical contamination of human health. In 2010, after 16 years of marriage, he filed for divorce from Richardson; she accused him of extensive infidelity, and he described her as abusive. Before the acrimonious proceedings concluded, Richardson committed suicide. In 2014, Kennedy married Hines. He has six children, two with Black and four with Richardson.

In his work as a litigator, he thrived: He won judgments against General Electric for contaminating the Hudson River; DuPont for contamination at a zinc-smelting plant in West Virginia; and Monsanto for a type of cancer allegedly caused by glyphosate, then the key ingredient of one of the world’s most popular herbicides, sold under the brand name Roundup. He argued many cases himself.

John Morgan, one of the nation’s most successful trial lawyers, worked with Kennedy on lawsuits after a natural-gas leak in Southern California in 2015 and the spectacular 2023 train derailment in East Palestine, Ohio. Morgan says there are three types of lawyers: finders, who get the plaintiffs; grinders, who try the cases; and minders, who keep it all on track. Kennedy was one of the best finders he’d ever met. “People follow him,” Morgan told me.

Although Kennedy has been litigating against environmental polluters for more than four decades, his focus on vaccines began only after mothers with autistic children started showing up at his talks—and after one of them persuaded him to read studies suggesting a link between vaccines and autism. The fact that vaccines can harm people is not contested: The existence of the National Vaccine Injury Compensation Program is a testament to the American public-health establishment’s acknowledgment of that. The frequency and nature of that harm, however, is highly contested. From 2006 to 2022, about 5 billion vaccine doses were distributed in the U.S. The NVICP paid about one settlement for every 1 million doses. Kennedy believes that the real rate of injury could be 100 times higher than what is reported. As in his crusade against corporate polluters, he brings a litigator’s tools to the vaccine fight—humanizing the victims, demonizing his opponents, and overwhelming his audiences with his research and with the nuclear force of his indignation.

Science, unlike fairy tales and courtroom dramas, does not always offer a clear narrative. Initial results may fail to replicate. Real findings can get drowned out by statistical noise. Catastrophic side effects may take time to emerge. In the evolving search for truth, the public can find itself whipsawed: Margarine was a healthy butter alternative—until studies found it to be a source of the artificial trans fats that cause 50,000 premature deaths a year. The Merck drug Vioxx was a miracle pain reliever—until researchers estimated that it was associated with as many as 140,000 excess cases of heart disease. The food pyramid of the 1990s, which emphasized processed carbohydrates over fiber and protein, now looks like a sick joke given what research has shown about the roots of our current obesity epidemic.

Kennedy thinks more people should follow his lead by consuming science directly. “ ‘Trusting the experts’ is not a feature of science,” he likes to say. “It’s not a feature of democracy. It’s a feature of totalitarianism and religion.” But having everyone “do their own research,” as Kennedy recommends, was untenable even before the advent of technologies like nanoscience and genomic editing. When I suggested to Kennedy that he was now presuming to play the role of health expert himself, he rejected that. “I don’t tell people to trust me. I tell people, ‘Don’t trust me.’ ”

Throughout our conversations, we often found ourselves jousting about the details of one scientific debate or another. For instance, I reminded Kennedy that back in 2005, he had suggested that the removal of thimerosal from most vaccines would result in a decline in autism diagnoses—but that since then, thimerosal had been removed from most vaccines, yet autism diagnoses continued to rise. He in turn argued that this could be explained by the addition of aluminum to vaccines during that same period, and by the fact that some flu vaccines still contained thimerosal. But most pregnant women and young children no longer receive flu vaccines with the preservative—and that’s been true since before Kennedy banned thimerosal from flu vaccines.

Another time, he pointed out that the U.S., a heavily COVID-vaccinated country, represents only 4.2 percent of the global population but accounts for 19 percent of the deaths from COVID. I countered that those differences are likely explained by other factors, including America’s more comprehensive reporting, higher chronic-disease rates, older population, and colder climate. He conceded all of that, but said he was making a narrower point, which was that the notion “that the only thing that saved us was the vaccine is unconvincing.”

He sent me a placebo-controlled COVID-vaccine study of pregnant women, conducted by Pfizer, which showed more congenital anomalies in babies born to the vaccinated group than the unvaccinated group. I countered that Pfizer had found the difference statistically insignificant. The reason the difference didn’t reach statistical significance, he pushed back, was that the study was not large enough and “Pfizer cut it off as soon as they saw a bad result.” If true, this suggested malicious intent on the part of the company. “Why aren’t you asking Pfizer about this?” he asked. “You should be burning up their phone line.”

So I called Pfizer, which granted me an interview with a scientist who was part of the company’s COVID-vaccine program, but requested that I not use the scientist’s name, to protect their privacy. This researcher told me that the study had been stopped not because of a bad result but because the data revealed no safety concerns with the vaccine—which meant that keeping the control group from getting it would have been unethical, given the serious risks stemming from COVID infection during pregnancy.

The researcher also explained that further investigation had determined that, of all the congenital anomalies initially reported, only one had originated after the vaccine administration, at 24 weeks’ gestation. “You cannot make a vaccine responsible for something that happened before you gave the vaccine,” the researcher told me.

When presented with data that contradict his arguments, Kennedy regularly claims bad faith on the part of his adversaries—that they’re motivated by profit or professional advancement. His experience as a litigator may have made this reflexive. As John Morgan, his litigation partner, told me, it’s hard to sue polluters and cigarette companies and not come away convinced that the defendants are “in the business of premeditated murder.” Kennedy has applied the same lens to the medical establishment, casting it as powered by the big pharmaceutical companies and their government protectors—despite the fact that most pediatricians and virologists and epidemiologists have devoted their lives to helping children and reducing suffering.

And if Kennedy is so concerned about conflicts of interest, what of his overhauled CDC vaccine panel? Some of the experts he appointed had previously been paid to serve as witnesses for plaintiffs in vaccine-safety lawsuits. Kennedy himself, in addition to the millions he made as a trial lawyer, took a large salary from Children’s Health Defense—$510,515 in 2022—a nonprofit he led from 2016 to 2023 that fundraises to fight for tighter vaccine regulation. His entire political project—his campaign, his hiring by Trump, his role at HHS—is entwined with his ability to prove that scientists were deceiving the public about vaccines. He would lose a lot if he changed his mind.

During his presidential campaign, Kennedy would repeatedly say that in a study of the COVID vaccine, Pfizer had found that “the people who got the vaccine had a 23 percent higher death rate from all causes at the end of that study”; he still says this today. He bases this on his interpretation of an early trial of the Pfizer COVID vaccine, and it sounds terrifying—a smoking gun for those looking for a reason to doubt official health advice. The main takeaway from that 2020 trial was that the rate of infection was significantly lower in the vaccinated group than in the placebo group (eight infections versus 162). The study followed about 44,000 people, who were randomly divided into two blinded groups, one that got the COVID vaccine and one that got a placebo shot. Over the course of six months, 21 people in the vaccine group and 17 in the placebo group died. (Scientists use these numbers to derive what they call “all-cause mortality rates.”) These are the numbers Kennedy uses to claim that a study found that your risk of death increases by 23 percent if you take the vaccine.

But the scientists I spoke with about Kennedy’s assertion explained that the study was not large enough and did not last long enough to reveal any increased mortality risk. In addition, an FDA review said none of the deaths in the study was vaccine-related. (Kennedy says this review was subjective.) Kennedy’s numbers were also misleading. During the blinded portion of the study, there were 15 deaths in the vaccine group, and 14 deaths in the group that received the placebo. (After the unblinding, the placebo group started getting the vaccine.) In 2023, Peter Doshi, an editor of a prestigious British medical journal, wrote Kennedy’s team an email advising that, based on these numbers, the proper conclusion about mortality from the study was that “there were basically equal numbers of deaths in vaccine and placebo arms.”

As we talked and texted this past fall, Kennedy and I kept returning to the same arguments we’d been having two years earlier. He would point to the all-cause mortality data from the Pfizer-vaccine study. I would respond that scientists who understood the data said they didn’t mean what he said they did—and I would point out that, even after the virus had mutated into new variants, observational studies continued to show that the Pfizer shot remained highly effective against both hospitalization and death.

Kennedy refused to relent. When the vaccines were introduced, he told me, public-health experts “were telling people, ‘This will save your lives.’ They didn’t have evidence for that. Twenty-three percent all-cause mortality! That’s not meaningful? I don’t know what universe you’re living in.”

Vaccinologists told me they’re living in a universe where they are trained to read and interpret data—not one in which you cherry-pick data from studies, extrapolate alarmist conclusions, and then suggest that they show a vaccine-caused increase in mortality when in fact they show nothing of the sort.

Like Bhattacharya, Kennedy tends to invoke Galileo. But in Kennedy’s telling, the villains were not only the clergy who arrested Galileo and censured his discoveries, but also the astronomer’s fellow scientists, who, wary of suffering his fate, refused to look through his telescope. It is a parable that posits unrecognized vaccine dangers as a sort of fixed point in the night sky, a supernova or moon, ready for discovery by anyone willing to risk their reputation in order to seek the truth.

Four days after Charlie Kirk’s death, Kennedy asked to speak with me again. He had his daughter Kick set up a Zoom call so that he would have a recording of our exchange. My efforts to transcend the divide were not going well.

“You kind of telegraphed where you were going,” he said when we convened that Sunday. “That there’s two sides that aren’t hearing each other, and both of them are intractable, and both of them think they are science-based.” He called this a journalistic device. “It’s a little bit self-serving because, you know, the journalist takes the position that ‘Okay, I’m looking at this phenomenon where there’s two sides and I’m in the middle’—the wise person who can kind of see everything,” he said. He suggested that he regretted agreeing to talk with me, and compared our relationship to the fable of the scorpion who asks the frog for help crossing a river, only to sting and kill the frog after it does.

“Every article about me is the same, which is never science-based; it’s never an argument; it’s always an ad hominem attack,” he continued. “ ‘He’s a conspiracy theorist, he’s anti-science, he’s a crazy person, he’s got a brain worm,’ or the bear story, or the whale story, or the dog story, any of these, and that’s what they focus on.” Articles about some of these colorful episodes from his past, he believed, were efforts to distract from the substance of his arguments. “I challenge you to tell me one conspiracy that I’ve talked about that has not come true,” he said. “Is it a conspiracy that I said that glyphosate—that Roundup—can cause cancer, like non-Hodgkin’s lymphoma? All three juries agreed with me. Is it a conspiracy theory that I said that the COVID vaccine was not going to prevent transmission? Now everybody admits that. Is it a conspiracy theory that I said that masks are not science-based? Everybody now agrees with that. School closures were a mistake.”

He wasn’t done. He fumed that people had used his interest in his father’s and uncle’s assassinations to discredit him. “I’ve never said my father was killed by the CIA. I’ve said there’s circumstantial evidence.” No one, he said, has explained the inconsistencies in his father’s autopsy, which contradicted the claim that his father’s sole killer was the Palestinian activist Sirhan Sirhan. “Robert Kennedy was shot from behind four times. We know what happened to every bullet in Sirhan’s gun. He hit six other people. He could not have killed my father. So, you know, that’s a fact. It’s science. And maybe you can figure out a way that he could’ve gotten behind my father.”

We were back where we started. “You know, a real journalist” would report that people were afraid of his arguments and that they were denying facts, he said, “but I don’t think The Atlantic will allow you to do that.”

“You’re the HHS secretary,” I said. “Presumably you can call anybody at CDC to have this debate.”

“There’s 21,000 people in that agency, and I’m not going to have a personal debate with each one of them,” he responded. “By the way, they’re leaving because they can’t defend their position.” Of course, the people quitting their jobs would dispute that. But to win in the court of public opinion, I suspected, Kennedy preferred to debate me.

This was all starting to seem rather hopeless. As I drafted this article, I felt growing dismay over my inability to establish even the basic factual common ground that scientific progress generally requires. So I sent Kennedy a message describing where I had ended up, and asking for another conversation. Minutes later, an adviser texted: “Want to meet at Secretary’s house today at 1 pm?”

Kennedy bought his new Georgetown home, not far from where Uncle Jack had lived as a congressman and senator, weeks after his confirmation. An interior doorway is decorated with signed notes to him from four recent Republican presidents—Gerald Ford, Ronald Reagan, George H. W. Bush, and Trump. I asked him why there were no letters from Barack Obama or Bill Clinton, the last presidents he’d campaigned for before Trump. “They’re in storage,” he said. An American flag from 1865 hangs in his living room, a companion, Kennedy told me, to one that was given to President Abraham Lincoln shortly before he was shot.

We started out by finding at least one point of agreement, the importance of free speech. In fact, Kennedy broke with many of his Republican brethren, saying that “anything that weaponizes Charlie Kirk’s death to justify censorship is not consistent with his values.”

Inevitably, though, we were soon back where we’d left off. Kennedy suggested that my story conclude by looking at a statement published on the CDC website—“Vaccines do not cause autism.” During the confirmation process, Bill Cassidy had made him promise not to remove the phrase in exchange for his vote. But Kennedy had a work-around. On November 19, he updated the page and put an asterisk next to the phrase, adding language stating that “studies have not ruled out the possibility that infant vaccines contribute to the development of autism.” Although the MMR vaccine and thimerosal have shown no ties to autism, Kennedy says he has not been able to find any studies of possible autism risk from various other childhood vaccines. This absence of research, he believes, undercuts the validity of the CDC website’s claim.

Kick joined us on the couch. Hines sat upstairs, running through the final edits of her memoir. I asked Kennedy: Was he now, as the nation’s health secretary, arguing that science showed vaccines caused autism, as he had in the past? Or was he simply arguing that the question had not been conclusively answered by science? He responded carefully. “I have opinions about things, but, you know, my opinions are irrelevant,” he said. “What we need is science, and we need definitive science. We have suggestive science.”

I had spoken with others about this point. They agreed with Kennedy that not every vaccine had been studied for its effect on autism rates. But they argued that doing so was not urgent, because the existing high-quality evidence around vaccines showed no connection. Joshua Gordon, who as the director of the National Institute of Mental Health helped oversee federal autism research, told me that the recent increase in autism rates could mostly be explained by broadened criteria for diagnosis and by the advancing average age of parents at the time of conception.

“If vaccines contribute to autism, it is such a very, very small effect that there is no question that if you did the study and you definitively showed the small effect, that small effect would be far outweighed by the benefit of vaccines,” Gordon told me. “The notion that after you did those studies you would come up with a different scientific recommendation is patently false.” When I asked him about the statement on the CDC website that Kennedy contests (“Vaccines do not cause autism”), Gordon said it was “a plain-English statement” that distilled the scientific consensus and was meant to encourage lifesaving vaccination.

Stanley Plotkin, one of the nation’s premier vaccinologists and the lead author of the medical-school textbook Plotkin’s Vaccines, had a similar message. “Can I say that vaccines do not cause autism?” he asked rhetorically. “All I can say is there is no evidence” that they do. He rejected some of the studies Kennedy cited as poorly conceived. He said he would not oppose a large new epidemiological study that looked at the issue, with the right design to take into account confounding variables. But he said he would not accept “a study constructed by a biased person with the objective of obtaining a certain result.”

Trump was duly elected, and he appointed Kennedy as HHS secretary to carry out priorities Trump had advanced during the campaign. This gives Kennedy’s scientific policies democratic legitimacy, even if trained health experts shudder at what that may mean. But as we sat in his living room, I realized that Kennedy was making an argument I had not previously understood—a policy claim, not a factual one. He was saying that regardless of the lives saved by vaccines, it was irresponsible for the government to recommend them without first comprehensively ruling out all hidden dangers. He believes that only a few vaccines, including the tuberculosis vaccine, have been studied enough to clear this bar. Kennedy had slashed the budget of his own department. But now, he says, he plans to spend billions of dollars on hundreds of studies investigating vaccines’ potential ties to chronic diseases. “The default setting in medicine is ‘Do no harm,’ ” he said, as we talked about the COVID-vaccine boosters. “You never do an intervention—particularly with a healthy human being—unless you know that it’s safe and effective. And we don’t know if it’s safe and effective.”

What if you are wrong about vaccines? I asked. Six former surgeons general, most vaccine experts, and almost the entire scientific establishment believes he is. What if, over time, the evidence shows that his actions lowered vaccination rates with no reduction in chronic diseases, but with an increase in suffering and death from viruses and bacteria? How would he respond?

“I mean, we would listen,” Kennedy said. It was the answer I wanted to hear. But then he listed, once again, the reasons he would not be wrong: He spoke about the chronic diseases that appear as potential adverse reactions on the manufacturers’ label for vaccines; the evidence that death rates from the diseases that vaccines inoculate against were already declining before the vaccines materialized; and America’s poor policy decisions and high mortality rates during the COVID years. “You know, we have all kinds of interventions,” he said. “Good health does not just come in a syringe.” The trial lawyer was still laboring to connect the dots that led to his preferred verdict, the orphaned child of American royalty, back from hell, still fighting to fulfill his birthright.

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This article appears in the January 2026 print edition with the headline “The Most Powerful Man in Science.”

Gas-station weed was never supposed to exist. And yet, convenience stores across the country—even in states where marijuana is illegal—sell a trove of fizzy drinks, vape pens, and confections all promising to get you high. My neighborhood liquor store has an entire cooler full of weed drinks, including a seltzer aptly named Bong Water, a can of which has 25 milligrams of THC. About five milligrams of that chemical, which is the main psychoactive component in marijuana, will make the occasional weed user feel a light buzz. If that’s not enough for you, you might be able to buy a vape pen with 5,000 milligrams at your corner store.

These products are available because Congress messed up. In 2018, it passed a bill that was meant to support farmers by allowing them to grow hemp—essentially, weed bred with minimal THC—for industrial uses such as paper, insulation, and even guitars. In the process, it also accidentally created a new industry of intoxicating hemp products that are virtually indistinguishable from those made using traditional marijuana, except for the fact that they’re federally legal.

If Congress has its way, however, such products could soon disappear. Tucked into the funding legislation that ended the government shutdown was a bill that would outlaw virtually any THC product not sold at a licensed dispensary—a mortal threat to the industry that’s brought Americans Trips Ahoy cookies and THC-infused Dorito knockoffs.

The particulars of the current loophole are wonky, but the law allows companies to sell any hemp product that doesn’t contain more than 0.3 percent THC by dry weight. A company selling a 40-gram cookie, for example, could add 100 milligrams of THC and still be under that limit. Crucially, this applies to products sold anywhere in the country. Kansas hasn’t legalized either recreational or medical cannabis, but as I’ve previously reported, when I went to Topeka in 2023, I was able to find intoxicating hemp products in 10 shops within an afternoon. In a state like Illinois, where legal marijuana abounds, the distinction between weed sold in licensed dispensaries and hemp sold at convenience stores might seem pedantic. But dispensaries have to follow rules meant to keep users safe, and they must keep the product cordoned off from people under 21. Sellers of THC-containing hemp products don’t have to follow the same rules. Technically, many states don’t even specify a minimum age to buy these products.

The downsides of this system were immediately apparent. In a recent nationwide survey, approximately 11 percent of high-school seniors reported trying hemp products that feature Delta 8, one of the mind-tweaking compounds found in marijuana. Mitch McConnell, who championed the amendment closing the loophole, said on the Senate floor during the debate over the bill that passing it would “keep these dangerous products out of the hands of children.” Plus, many of these technically legal hemp products are filled with potentially dangerous synthetic compounds. Delta 8, for example, naturally occurs in marijuana only in very small amounts, so the substance added to vapes and drinks is typically created by chemically manipulating CBD, a more prevalent compound in the plant. The FDA has warned that this process may include “potentially unsafe household chemicals” and may be done “in uncontrolled or unsanitary settings, which may lead to the presence of unsafe contaminants or other potentially harmful substances.”

[Read: The new war on weed]

Now, after seven years, Congress has decided that enough is enough. Under the new funding bill, any product with more than 0.4 milligrams total THC—virtually nothing—would be considered a Schedule I narcotic, just like heroin, LSD, and regular old marijuana. The law will for the most part not affect dispensaries in states that have legalized weed, but it will make more than 95 percent of the current hemp market illegal, Jonathan Miller, a lobbyist for the industry group U.S. Hemp Roundtable, told me. And that’s the point: I asked Kevin Sabet, who runs an anti-marijuana group that lobbied for the new legislation on Capitol Hill, what successful implementation would look like. “A lot of the major players out of business,” he told me.

The new legislation doesn’t go into effect for a year, and already, the hemp industry is trying to persuade lawmakers to call off the crackdown. When I spoke with Miller on Tuesday, he told me that he was set to discuss the issue with an influential member of Congress the next day. The Hemp Roundtable, which spent $320,000 lobbying Congress last year, is hoping to persuade lawmakers to abandon the 0.4-milligram THC limit for something more workable—perhaps five or 10 milligrams, Miller told me. Ed Marszewski, the president of Marz Community Brewing Co., which makes Bong Water, told me that his company also wants regulations on serving sizes for hemp products, as well as age restrictions and safety testing.

Hemp companies might also wait to see how the new law will be enforced before taking any dramatic action. Despite the 2018 hemp loophole, selling food to which THC or CBD has been added is unequivocally prohibited by the FDA. However, the agency has typically gone after only those companies making unsubstantiated health claims or marketing their products to kids, Jonathan Havens, a cannabis attorney at the law firm Saul Ewing, told me. Since 2018, roughly 100 companies have received warnings from the FDA for selling cannabis-containing products. The industry, clearly, has kept on making its forbidden treats.

[Read: Marijuana is too strong now]

The question is whether the status quo changes in 2027, given the higher stakes. Selling a Schedule I narcotic typically carries a stiffer penalty than violating FDA rules does. But the Drug Enforcement Administration doesn’t currently have the resources to surveil every gas station, smoke shop, and liquor store in the country, and closely policing those settings would mean taking agents off more serious cases, Jim Crotty, a former DEA official, told me. (The DEA did not respond to a request for comment.) The federal government hasn’t shown a willingness to police local cannabis sales in the past: Licensed marijuana dispensaries are technically illegal under federal law too, but the feds have typically not interfered with shops that abide by state law. A similar scenario could play out with hemp products, Douglas Berman, the executive director of the Drug Enforcement and Policy Center at Ohio State University, told me.

Proponents of this new law may hope that the days of hemp gummies and seltzers are limited. But passing a policy like this is easy compared with the work required to enforce it. Americans may soon find out if the government is up to the job.

Let me make a small concession on behalf of the medical community: The CDC is technically correct when it asserts, as it did this week in a surprise update to its website, that “studies have not ruled out the possibility that infant vaccines cause autism.” But the underlying logic of this change clearly goes beyond the wispy double negative. Robert F. Kennedy Jr. has already said that he believes in the affirmative: Vaccines do cause autism. And because he is now secretary of Health and Human Services, he can order his bureaucracy to lean ever further toward that same belief. A causal link hasn’t not been found, the CDC is saying now—at least not completely, not quite yet.

If this pretzel logic is confusing, that’s the point. Bewilderment and doubt are among the anti-vaccine movement’s most powerful weapons. It’s true that doctors cannot say with absolute certainty that some ingredient in some vaccine, or combination of vaccines, does not contribute in some way, however small or large, to the rise in autism diagnoses. We also can’t rule out the possibility that infant vaccines cause tornadoes or bad movies. Uncertainty is inseparable from science.

[Read: The CDC’s website is anti-vaccine now]

Kennedy has firsthand knowledge of how difficult it is to prove a medical assertion. He began his crusade against immunizations 20 years ago, with the argument that the vaccine preservative thimerosal was causing a spike in autism rates. In his discredited 2005 article on the topic, he said he was “convinced that the link between thimerosal and the epidemic of childhood neurological disorders is real.” In fact, the evidence was very weak, and additional real-world observations have further undermined his claim. Throughout the 1990s and 2000s, thimerosal was removed, as a precaution, from childhood inoculations in many developed countries, and yet autism diagnoses continued to climb. Denmark took the preservative out of its shots in 1992, for instance, yet experienced a fivefold increase in autism diagnoses among young children by the end of the millennium.

In a New York Times interview yesterday, Kennedy acknowledged that studies had shown no link between thimerosal and autism. But he and his fellow anti-vaccine activists are undeterred by this contradiction. They have expressed little, if any, regret about their misguided crusade. (In fact, Kennedy has lately taken his anti-thimerosal campaign global.) But even if they were to grant that this ingredient is not, in fact, a cause of autism, they’d still be pointing at all the other vaccine components. Can each and every one be ruled out as a risk? Notably, the word thimerosal does not appear in this week’s update from the CDC. (A separate, preexisting page on CDC.gov says that the preservative has “no connection with autism.”) Instead the agency now points to another boogeyman ingredient: aluminum. That’s what warrants “further investigation,” circa 2025. (HHS Press Secretary Emily Hilliard told me that Kennedy supports the removal of thimerosal from all U.S. influenza vaccines, and that his “comprehensive review of autism’s causes” will emphasize “transparency, reproducibility, and gold-standard science.”)

[Read: The U.S. is going backwards on vaccines, very fast]

Kennedy has a clever way of playing with the evidence: He will hack apart robust results that support the safety of vaccines while canonizing any bit of information that could be seen to go the other way. The CDC-website update is a perfect specimen of this disordered scientific thinking. It shows how drops of doubt can be squeezed from even the most rock-solid data. One of the site’s citations, for example, is to a major study of aluminum-based vaccines that came out in the Annals of Internal Medicine earlier this year. Danish researchers examined the medical records of more than 1 million children and found no association between the amount of aluminum present in vaccines administered early in life and 50 different medical conditions. When that analysis was published, Kennedy demanded that it be retracted: “The only thing this study proves is the thorough corruption of the scientific journals that publish such garbage-in, garbage-out exercises in statistical manipulation,” he wrote in an op-ed last August. Yet now, improbably, the CDC is pointing to this very study in support of its double-negative conclusion. Are aluminum vaccines a cause of autism? Not necessarily no.

Echoing Kennedy’s assertions, the CDC site maintains that one should just ignore the Danish study’s overall results in favor of its secret truth. The paper’s real result, it suggests, is hidden in the supplementary tables, where one reveals that “moderate” aluminum exposure is linked to higher rates of neurodevelopmental conditions. But on closer look, the table also shows that any such relationship disappears at higher doses of aluminum—a quirky finding that should make the whole idea appear unsound.

The CDC continues on to cite aluminum’s apparent link to reported diagnoses of Asperger’s syndrome. This conclusion, too, is highly suspect: The data point in question, buried in supplemental figure 4, was seen only in a tiny subsample of 51 children with the condition. A more complete analysis of 3,000 children with neurologic disorders in the study found something like the opposite: Greater levels of aluminum were associated with fewer problems. None of this should be treated as a demonstration that aluminum-based vaccines are dangerous or beneficial; the details of these supplemental tables show only that science is a messy business. (Anders Hviid, the senior author of the paper, has responded to Kennedy’s assertions by maintaining that his study “does not provide support for the hypothesis that aluminum used as adjuvants in vaccines are associated with increased risks of early childhood health conditions.”)

The best doctors are aware of all these opportunities for confusion. Well-calibrated doubt is an important tool in medicine—more essential than a stethoscope or an X-ray—and the uncertainties it yields should be acknowledged and communicated. So why do physicians keep insisting that vaccines don’t cause autism? They are not “lying to you,” as Kennedy has alleged. Instead, they are doing what doctors are supposed to do: digesting a large amount of information in order to produce the most reasonable conclusion. They know that double negatives don’t help in matters of life and death. (As a pathologist, I try not to tell patients, “Well, you don’t not have cancer.”) Professional skeptics like Kennedy thrive on raising questions—but the public thrives on getting answers.

If Robert F. Kennedy Jr., the secretary of Health and Human Services, did bother to ask CDC scientists about using their website to turn anti-vaccine talking points into agency guidance, it didn’t matter much. “My understanding is that none of the leadership were asked about it, or if they were asked about changing the website, they did not agree with the change,” Daniel Jernigan, the former director of the National Center for Emerging and Zoonotic Infectious Diseases, told me. But as of last night, there it was: The CDC’s new official stance is that “studies have not ruled out the possibility” that routine childhood immunizations contribute to autism.

A senior CDC scientist told me that many people at the agency heard about the change only yesterday evening, hours before the revamped website launched. The decision appears not to have passed through the normal channels, which would involve staff at the Immunization Safety Office, Jernigan said. When asked via email whether CDC scientists had been bypassed, Andrew Nixon, an HHS spokesperson, didn’t answer. Instead, he reiterated bullet points from the website update, including the claim that studies supporting a link between autism and vaccines “have been ignored by health authorities”—essentially, the CDC accusing itself of having disregarded scientific evidence.

The new language appears in the “Vaccine Safety” section of the agency’s website. Until yesterday, that page laid out autism researchers’ long-standing consensus that vaccines do not cause the disorder. It noted that no link has been found between vaccine ingredients and autism, and that a National Academy of Medicine review of eight routine immunizations found that, “with rare exceptions, these vaccines are very safe.” The website’s affirmation that vaccines do not cause autism was important enough that during Kennedy’s confirmation process earlier this year, Senator Bill Cassidy, a physician, made him promise not to remove it. But instead of keeping his promise, Kennedy—who oversees the CDC as head of HHS—appears to be using the CDC website to advance his own anti-vaccine beliefs.

Technically, the statement “Vaccines do not cause autism” has not been removed from the CDC website. Instead, it has been appended with an asterisk, which is explained at the bottom of the page: “The header ‘Vaccines do not cause autism’ has not been removed due to an agreement with the chair of the U.S. Senate Health, Education, Labor, and Pensions Committee that it would remain on the CDC website.” That asterisk is an obvious farce, because the page is now devoted to undermining the scientific consensus. “‘Vaccines do not cause autism’ is not an evidence-based claim,” the site now states, despite the fact that multiple large studies have found no such association. The site notes that reviews on the measles, mumps, and rubella vaccine concluded that there is no association between the MMR vaccine and autism—but goes on to criticize those reviews as methodologically flawed. It also asserts that the rise in autism rates “correlates with the rise in the number of vaccines given to infants.”

In fact, autism researchers attribute much of that increase to improved screening and broader diagnostic criteria. Studies suggest that about 80 percent of a person’s autism risk comes from inherited mutations in their DNA. (The webpage doesn’t mention genes.) And yet, parents considering whether to vaccinate their child and seeking the CDC’s advice will now get the impression not only that the jury is out on whether vaccines cause autism but also that there is reason to believe they do.

[Read: The U.S. is going backwards on vaccines, very fast]

Kennedy himself has suggested as much for years in books and interviews, and as chair of the anti-vaccine nonprofit Children’s Health Defense. Such statements raised Cassidy’s suspicions during Kennedy’s confirmation process, though Cassidy still voted him into office. Demetre Daskalakis, who was the director of the National Center for Immunization and Respiratory Diseases before resigning alongside Jernigan and former CDC Chief Medical Officer Debra Houry, told me that it seemed to him that Kennedy had tricked Cassidy. “It’s a slap in the face,” he said. (Cassidy’s office did not respond to a request for comment. When reporters for Punchbowl News asked the senator today to comment on Kennedy’s broken promise, he lamented the “double tragedy” of falling vaccine rates and resources being wasted investigating “things we know do not cause autism,” but said nothing about Kennedy.)

Changing the website won’t affect the availability of routine vaccinations for children, at least not in the short term. It could, however, signal an intent by HHS to make it easier for parents of autistic children to pursue claims through the National Vaccine Injury Compensation Program. Houry told me she worries that the cherry-picked evidence on the new site will make parents hesitate over vaccinating their children against dangerous illnesses. In a statement, the Autism Science Foundation condemned the change, saying that the CDC’s vaccine-safety page “is now filled with anti-vaccine rhetoric and outright lies about vaccines and autism.”

Since taking office, Kennedy has been careful to moderate some of his more strident anti-vaccine views, at least in public. During his confirmation hearing, he insisted that he is not anti-vaccine, though he sidestepped questions about whether immunizations cause autism, saying that he would look at the data. In the midst of a measles outbreak in West Texas earlier this year, he paid lip service to the fact that vaccines protect children and the community, but in private, he was more openly conspiratorial. As the father of a girl who died from the measles told me in April, Kennedy said to him that we “don’t know what’s in the vaccine anymore.” Kennedy also fired the CDC’s outside vaccine advisers and replaced them with allies whose views are closer to his own—flouting another promise to Cassidy that he would maintain the advisory board “without changes.”

[Read: Bill Cassidy’s failure on vaccines]

All of those moves broke norms and sowed doubt about vaccines. But if they were a dog whistle, the new CDC website is a siren. Kennedy’s most radical doubts about vaccines have now been enshrined as official government guidance. Children’s Health Defense praised the website change on X, calling it “the biggest public health reversal of our lifetime.” It is indeed.