For a few hours, Pete Hegseth’s nomination as secretary of defense was the most disturbing act of Donald Trump’s presidential transition. Surely the Senate wouldn’t confirm an angry Fox News talking head with no serious managerial experience, best known for publicly defending war criminals, to run the largest department in the federal government. Then, in rapid succession, Trump announced appointments for Matt Gaetz, Tulsi Gabbard, and Robert F. Kennedy Jr. The appearance of these newer and even more aberrant characters, like a television show introducing a more villainous heel in its second season, muted the indignation over Hegseth.

Obscured in this flurry of shocking appointments is the fact that Hegseth’s drawbacks are not limited to his light résumé or to the sexual-assault allegation made against him. Inexperienced though he may be at managing bureaucracies, Hegseth has devoted a great deal of time to documenting his worldview, including three books published in the past four years. I spent the previous week reading them: The man who emerges from the page appears to have sunk deeply into conspiracy theories that are bizarre even by contemporary Republican standards but that have attracted strangely little attention. He considers himself to be at war with basically everybody to Trump’s left, and it is by no means clear that he means war metaphorically. He may be no less nutty than any of Trump’s more controversial nominees. And given the power he is likely to hold—command over 2 million American military personnel—he is almost certainly far more dangerous than any of them.

Hegseth began his involvement in conservative-movement politics as a Princeton undergraduate. He then joined the Army and quickly developed a profile, when not on active duty, as a budding Republican spokesperson. He testified against Elena Kagan’s appointment to the Supreme Court (on the grounds that, while dean of Harvard Law School, she had blocked military recruiters from campus in protest of Don’t Ask, Don’t Tell) and lobbied in favor of the Bush administration’s Iraq policy. As the Republican Party’s foreign-policy orientation changed radically under Donald Trump, Hegseth’s positions changed with it. But his devotion to the party remained constant. After stints running the advocacy groups Vets for Freedom and Concerned Veterans for America, and a failed Senate campaign, he finally settled at Fox News, where he joined a chorus in support of Trump.

Along the way, Hegseth has written five books. The first, extolling Teddy Roosevelt’s legacy, revolves around ideas that Hegseth has since renounced after converting to Trumpism. Another is simply a collection of war stories. The other three, all published in the past four years—American Crusade (2020), Battle for the American Mind (2022), and The War on Warriors (2024)—lay out his worldview in florid, explicit, and often terrifying detail.

A foundational tenet of Hegseth’s philosophy, apparently carrying over from his Roosevelt-worshipping era, is a belief in the traditional masculine virtues and the potential for war to inculcate them. Hegseth maintains that boys require discipline and must aspire to strength, resilience, and bravery. His preferred archetype for these virtues appears to be Pete Hegseth, whose manful exploits either on the basketball court (he played for Princeton) or the battlefield are featured in all three books.

[David A. Graham: The perverse logic of Trump’s nomination circus]

Hegseth complains that society no longer gives veterans like him their proper measure of deference. “Being a veteran no longer demands respect of the coastal elites or reverence from large swaths of the public,” he writes—an observation that will sound strange to anybody who has ever attended a football game or listened to a speech by a politician from either party. “In previous generations, men had to find ways to salvage their honor if they didn’t get to fight in a war.” (The single strongest piece of evidence for Hegseth’s thesis—the popularity of lifelong coastal elitist, proud war-avoider, and POW-mocker Donald Trump—goes unmentioned).

Hegseth’s demand for greater respect grows out of his belief that he personally succeeded in the face of forbidding odds. “I had been an underdog my whole life,” he writes. “I persisted. I worked my ass off.” But the woke military, he complains, doesn’t reward that kind of individual merit and grit. Instead, it has grown so obsessed with diversity that it promotes unqualified minorities and allows women in combat, reducing its effectiveness and alienating hard-working, meritorious soldiers such as, well, him. He also frets that the inclusion of women in combat erodes traditional gender norms. “How do you treat women in a combat situation,” he asks, “without eroding the basic instinct of civilization and the treatment of women in the society at large?”

(The treatment of women by Hegseth specifically happens to be the subject of a recently disclosed police report detailing an alleged sexual assault of a woman at a 2017 political conference. Hegseth denies the allegation and says that the encounter, which took place while he was transitioning between his second and third wives, was consensual. He paid the alleged victim an undisclosed sum in return for her signing a nondisclosure agreement.)

One episode looms especially large in Hegseth’s mind as the embodiment of the wokification of the military and its abandonment of traditional merit. In 2021, Hegseth, an active National Guard member, wished to join the Washington, D.C., unit protecting incoming President Joe Biden’s inauguration. The National Guard, however, excluded him from the detail because he was deemed a security risk on account of a bicep tattoo of the “Deus Vult” symbol—a reference to the Crusades that is popular with some far-right activists.

The logic of the snub was straightforward. Biden’s inauguration took place in the immediate aftermath of an insurrection attempt that had included many members of the armed forces, some operating within far-right networks. But to Hegseth—who protests that the Deus Vult tattoo is simply an expression of his Christian faith, not a white-nationalist symbol—the decision was an unforgivable personal affront.

He expresses indignation at the notion that he could even be suspected of harboring radical ideas. “I fought religious extremists for over twenty years in uniform,” he writes. “Then I was accused of being one.” This is not as paradoxical as Hegseth makes it sound. Many of the people most eager to fight against extremists of one religion are extremist adherents of another religion. An example of this would be the Crusades, an episode that Hegseth highlights in American Crusade as a model to emulate.

In any case, evidence of Hegseth’s extremism does not need to be deduced by interpreting his tattoos. The proof is lying in plain sight. In his three most recent books, Hegseth puts forward a wide range of familiarly misguided ideas: vaccines are “poisonous”; climate change is a hoax (they used to warn about global cooling, you know); George Floyd died of a drug overdose and was not murdered; the Holocaust was perpetrated by “German socialists.”

Where Hegseth’s thinking begins venturing into truly odd territory is his argument, developed in Battle for the American Mind, that the entire basic design of the public education system is the product of a century-long, totally successful communist plot. Hegseth is not just hyperventilating about the 1619 Project, Howard Zinn, or other left-wing fads, as conservatives often do. Instead he argues that the entire design of the U.S. education system is a Marxist scheme with roots going back to the founding of the republic. The deist heresies of Ben Franklin and Thomas Jefferson, he writes, laid the groundwork to implant communist thought into the school system. Then, “American Progressives in the late 1800s blended the idea of Marxist government with aspects from the Social Gospel and the belief in an American national destiny in order to make Marxism more palatable to Americans.”

The nefarious plan to turn America communist involves steps that appear anodyne to the untrained eye. “Yes, our modern social sciences—like ‘political science,’ previously known as ‘politics,’ and ‘social studies,’ previously known as individual disciplines like ‘history, economics, geography and philosophy’—are byproducts of Marxist philosophy,” he writes. “Let that sink in: the manner in which we study politics, history, and economics in American schools—public and private—today is the product of Marxists. That was always the plan, and it worked.” Hegseth will no longer sit back and allow communist indoctrination to sap and impurify our precious bodily fluids.

The Marxist conspiracy has also, according to Hegseth, begun creeping into the U.S. military, the institution he is now poised to run. His most recent book calls for a straightforward political purge of military brass who had the gall to obey Democratic administrations: “Fire any general who has carried water for Obama and Biden’s extraconstitutional and agenda-driven transformation of our military.” Trump appears to be thinking along similar lines. He is reportedly working on an executive order that will fast-track the removal of officers “lacking in requisite leadership qualities” and compiling a list of officers involved in the Afghanistan retreat, who will likewise be shoved out.

To what end? Trump has already signaled his interest in two revolutionary changes to the Defense Department’s orientation. One is to legalize war crimes, or at least cease enforcement of the rules of war. The president-elect has enthusiastically endorsed the use of illegal military methods and has pardoned American soldiers who committed atrocities against detainees and unarmed civilians, following a loud campaign by Hegseth on Fox News.

[Graeme Wood: War crimes are not difficult to discern]

In The War on Warriors, Hegseth makes plain that he considers the very idea of “rules of war” just more woke nonsense. “Modern war-fighters fight lawyers as much as we fight bad guys,” he writes. “Our enemies should get bullets, not attorneys.” He repeatedly disparages Army lawyers (“jagoffs”), even claiming that their pointless rules are “why America hasn’t won a war since World War II.” (Ideally, the secretary of defense would be familiar with historical episodes such as the Gulf War.)

Writing about his time guarding prisoners at Guantánamo Bay—where, as even the Bush administration eventually admitted, most detainees were innocent men swept up by American forces—Hegseth describes calls for due process as a stab-in-the-back against brave soldiers like himself. “The nation was dealing with legal issues (mostly led by weak-kneed, America-hating ACLU types) concerning enemy combatants, ‘international rights’ of illegal combatants, and the beginnings of extrajudicial drone attacks,” he writes. “Not to mention the debate about the ‘rights’ of assholes (I mean, ‘detainees’) at Gitmo.”

Trump’s second and even more disturbing interest in having a loyalist run the department is his enthusiasm for deploying troops to curtail and if necessary shoot domestic protesters. His first-term defense secretaries blanched at these demands. Hegseth displays every sign of sharing Trump’s impulses, but in a more theorized form.

The clearest throughline of all three books is the cross-application of Hegseth’s wartime mentality to his struggle against domestic opponents. American Crusade calls for the “categorical defeat of the Left,” with the goal of “utter annihilation,” without which “America cannot, and will not, survive.” Are the Crusades just a metaphor? Sort of, but not really: “Our American Crusade is not about literal swords, and our fight is not with guns. Yet.” (Emphasis—gulp—his).

Battle for the American Mind likewise imagines the struggle against the communist educational plot as a military problem: “We are pinned down, caught in an enemy near ambush. The enemy has the high ground, and is shooting from concealed and fortified positions.”

And The War on Warriors repeatedly urges Hegseth’s readers to treat the American left exactly like foreign combatants. Describing the military’s responsibility to the nation, he writes, “The expectation is that we will defend it against all enemies—both foreign and domestic. Not political opponents, but real enemies. (Yes, Marxists are our enemies.)” The Marxist exception swallows the “not political opponents” rule, because pretty much all of his political opponents turn out to be Marxists. These include, but are not limited to, diversity advocates (“They are Marxists … You know what they are? They’re traitors”), newspapers (“the communist Star Tribune”), and, as noted, almost anybody involved in public education.

Lest there be any ambiguity, Hegseth incessantly equates the left to wartime enemies. “They do not respect cease-fires, do not abide by the rules of warfare, and do not respect anything except total defeat of their enemy—and then total control,” he writes at one point. At another, he argues, “We should be in panic mode. Almost desperate. Willing to do anything to defeat the ‘fundamental transformation’ of the American military and end the war on our warriors.”

Hegseth’s idea of illegitimate behavior by the domestic enemy is quite expansive. Consider this passage, recalling his time advocating for the Iraq War: “While I debated these things in good faith, the Left mobilized. Electing Obama, railroading the military, pushing women in combat—readiness be damned. The left has never fought fair.” The most remarkable phrase there is “electing Obama.” Hegseth’s notion of unfair tactics used by the left includes not only enacting administrative policies that he disagrees with, but the basic act of voting for Democrats. The inability or unwillingness to distinguish between legitimate and illegitimate political opposition likely endeared Hegseth to Trump, who shares the trait.

A Defense Secretary with a tenuous grip on reality, who can’t differentiate foreign enemies from domestic political opponents, and who seems to exist in a state of permanent hysteria is a problem that the United States has never had to survive. The main question I was looking to answer when I started reading Hegseth’s collected works was whether he would follow a Trump command to shoot peaceful protesters. After having read them, I don’t think he would even wait for the order.

When I was taking German in college in the early years of this millennium, I once stumbled upon a word that appeared foreign even when translated into English: Diphtherie, or diphtheria. “What’s diphtheria?” I wondered, having never encountered a single soul afflicted by this disease.

Diphtheria, once known as the “strangling angel,” was a leading killer of children into the early 20th century. The bacterial infection destroys the lining of the throat, forming a layer of dead, leathery tissue that can cause death by suffocation. The disease left no corner of society untouched: Diphtheria killed Queen Victoria’s daughter, and the children of Presidents Lincoln, Garfield, and Cleveland. Parents used to speak of their first and second families, an elderly woman in Ottawa recalled, because diphtheria had swept through and all their children died.

Today, diphtheria has been so thoroughly forgotten that someone like me, born some 60 years after the invention of a diphtheria vaccine, might have no inkling of the fear it once inspired. If you have encountered diphtheria outside of the historical context, it’s likely because you have scrutinized a childhood immunization schedule: It is the “D” in the DTaP vaccine.

Vaccine breakthroughs over the past two centuries have cumulatively made the modern world a far more hospitable place to be born. For most of human history, half of all children died before reaching age 15; that number is down to just 4 percent worldwide, and far lower in developed countries, with vaccines one of the major drivers of improved life expectancy. “As a child,” the vaccine scientist Stanley Plotkin, now 92, told me, “I had several infectious diseases that almost killed me.” He ticked them off: pertussis, influenza, pneumococcal pneumonia—all of which children today are routinely vaccinated against.

But the success of vaccines has also allowed for a modern amnesia about the level of past human suffering. In a world where the ravages of polio or measles are remote, the risks of vaccines—whether imagined, or real but minute—are able to loom much larger in the minds of parents. This is the space exploited by Robert F. Kennedy Jr., one of the nation’s foremost anti-vaccine activists and now nominee for secretary of Health and Human Services. It is a stunning reversal of fortune for a man relegated to the fringes of the Democratic Party just last year. And it is also a reversal for Donald Trump, who might have flirted with anti-vaccine rhetoric in the past but also presided over a record-breaking race to create a COVID vaccine. Kennedy has promised that he would not yank vaccines off the market, but his nomination normalizes and emboldens the anti-vaccine movement. The danger now is that diseases confined to the past become diseases of the future.

Walt Orenstein trained as a pediatrician in the 1970s, when he often saw children with meningitis—a dangerous infection of membranes around the brain—that can be caused by a bacterium called Haemophilus influenzae type b or Hib. (Despite the name, it is not related to the influenza virus.) “I remember doing loads of spinal taps,” he told me, to diagnose the disease. The advent of a Hib vaccine in the 1980s virtually wiped these infections out; babies are now routinely vaccinated in the first 15 months of life. “It’s amazing there are people today calling themselves pediatricians who have never seen a case of Hib,” he says. He remembers rotavirus, too, back when it used to cause about half of all hospitalizations for diarrhea in kids under 5. “People used to say, ‘Don’t get the infant ward during diarrhea season,’” Orenstein told me. But in the 2000s, the introduction of rotavirus vaccines for babies six months and younger sharply curtailed hospitalizations.

To Orenstein, it is important that the current rotavirus vaccine has proved effective but also safe. An older rotavirus vaccine was taken off the market in 1999 when regulators learned that it gave babies an up to one-in-10,000 chance of developing a serious but usually treatable bowel obstruction called intussusception. The benefits arguably still outweighed the risks—about one in 50 babies infected with rotavirus need hospitalization—but the United States has a high bar for vaccine safety. Similarly, the U.S. switched from an oral polio vaccine containing live, weakened virus—which had a one in 2.4 million chance of causing paralysis—to a more expensive but safer shot made with inactivated viruses that cannot cause disease. No vaccine is perfect, says Gregory Poland, a vaccinologist and the president of the Atria Academy of Science & Medicine, who himself developed severe tinnitus after getting the COVID vaccine. “There will always be risks,” he told me, and he acknowledges the need to speak candidly about them. But vaccine recommendations are based on benefits that are “overwhelming” compared with their risks, he said.

The success of childhood vaccination has a perverse effect of making the benefits of these vaccines invisible. Let’s put it this way: If everyone around me is vaccinated for diphtheria but I am not, I still have virtually no chance of contracting it. There is simply no one to give it to me. This protection is also known as “herd immunity” or “community protection.” But that logic falls apart when vaccination rates slip, and the bubble of protective immunity dissolves. The impact won’t be immediate. “If we stopped vaccinating today, we wouldn’t get outbreaks tomorrow,” Orenstein said. In time, though, all-but-forgotten diseases could once again find a foothold, sickening those who chose not to be vaccinated but also those who could not be vaccinated, such as people with certain medical conditions and newborns too young for shots. In aggregate, individual decisions to refuse vaccines end up having far-reaching consequences.

Evolutionary biologists have argued that plague and pestilence rose in tandem with human civilization. Before humans built cities, back when we still lived in small bands of hunter-gatherers, a novel virus—say, from a bat—might tear through a group only to reach a dead end once everyone was immune or deceased. With no one else to infect, such a virus will burn itself out. Only when humans started clustering in large cities could certain viruses keep finding new susceptibles—babies or new migrants with no immunity, people with waning immunity—and smolder on and on and on. Infectious disease, you might then say, is a necessary condition of living in a society.

But human ingenuity has handed us a cheat code: Vaccines now allow us to enjoy the benefits of fellow humanity while preventing the constant exchange of deadly pathogens. And vaccines can, through the power of herd immunity, protect even those who are too young or too sick to be effectively vaccinated themselves. When we get vaccinated, or don’t, our decisions ricochet through the lives of others. Vaccines make us responsible for more than ourselves. And is that not what it means to live in a society?

Robert F. Kennedy Jr., the bear-fondling, gravel-voiced Camelot scion, is President-Elect Donald Trump’s pick to lead the Department of Health and Human Services, where presumably he will “go wild on health,” to quote Trump. His nomination has raised concerns among public-health experts because many of Kennedy’s views on health are, well, wild.

To be sure, among Kennedy’s battier ideas are a few reasonable ones, such as reducing obesity and cracking down on direct-to-consumer drug commercials and conflicts of interest among researchers. But these are eclipsed by some troubling ones, such as the ideas that common cooking oils are poisonous, that fluoride doesn’t belong in tap water, and that childhood vaccines are questionable.

What if Kennedy did, in fact, go wild on health, get his way, and remake America in his own image? If his worst ideas come to pass, experts tell me, heart attacks might increase, dental infections might spike, and children might needlessly die of completely preventable diseases.

[Read: RFK Jr. collects his reward]

Even if he is confirmed as health secretary, Kennedy’s influence on some of these domains might be limited. Most public-health measures—including water fluoridation and vaccines—are a matter for states and localities, not the federal government. (This is why different states had such different COVID-19 responses.) But even so, a Secretary Kennedy would have a prominent perch from which to espouse his ideas, and his position would give him a veneer of credibility that he has not earned. Right-leaning states and judges might listen, and adapt local policies to suit his worldview. At the very least, parents who support Trump and Kennedy might take the administration’s views into account when making decisions for their families.

Let’s begin with seed oils, which keep popping up in Kennedy’s speeches and media clips. (He even mentioned them while suspending his presidential bid.) Kennedy has called seed oils, which include common cooking oils such as canola oil and sunflower oil, “one of the most unhealthy ingredients that we have in foods,” and says Americans are being “unknowingly poisoned” by them.

Kennedy believes that seed oils cause “body-wide inflammation” and disease. But this isn’t true, Christopher Gardner, a nutrition scientist at Stanford, told me. In fact, replacing foods high in saturated fat, such as butter, with those high in unsaturated fat, such as canola oil, has been proven again and again to lower cholesterol levels and reduce the risk of heart disease. To the extent that seed oils are bad, Gardner said, it’s because they often show up in highly processed junk and fast food.

And Kennedy’s solution to this supposed health crisis—to replace seed oils with beef tallow—is troubling. (Several of his seed-oil clips end with a promo of red Kennedy swag that reads MAKE FRYING OIL TALLOW AGAIN.) Whatever you do with seed oil, “don’t replace it with beef tallow,” Gardner said. “That’s friggin’ nuts.” Replacing all the oil you eat with beef fat can cause cholesterol to pile into plaques in your arteries, impeding the flow of blood. “That’s how you get a heart attack,” Gardner said.

Kennedy has also said he wants to remove fluoride from tap water, claiming that the compound is an “industrial waste associated with arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders, and thyroid disease.”

There is some risk associated with excessive fluoride intake: Consuming fluoride above a level of 1.5 milligrams a liter—about twice the level that’s in most fluoridated tap water—has been linked to lowered IQ in children. Fluoridated water can also cause light stains on teeth, which affect about 12 percent of people in the United States.

But researchers say these risks are generally worth it because the consequences of removing fluoride from the water are much worse. Fluoride helps strengthen tooth enamel, and it also fights off the acid that attacks our teeth any time we eat carbohydrates. If the teeth lose this battle, decay can set in—and if the decay goes untreated, it can cause excruciating pain and, in extreme cases, pus-filled abscesses. “There will certainly be an increase in dental decay if fluoride is removed from the drinking water,” Gary Slade, a dentistry professor at the University of North Carolina at Chapel Hill, told me. Slade found in a study that fluoride in drinking water reduces decay by 30 percent in baby teeth and 12 percent in permanent teeth.

Some cities and countries have removed fluoride from the water, and kids’ dental health suffered as a result. After Israel ceased water fluoridation in 2014, dental treatments in a clinic in Tel Aviv increased twofold across all ages. In Canada, after Calgary ceased water fluoridation in 2011, second graders there experienced more cavities than those in Edmonton, where water was still fluoridated. After Juneau, Alaska, ceased water fluoridation in 2007, children younger than 6 underwent more cavity-related dental procedures—at a cost of about $300 more a year per child. Some cities have even reintroduced fluoride into the water supply after noticing an uptick in tooth decay among children.

Kennedy is perhaps most infamous for his skepticism of vaccines, and this is also likely the issue where his views are most consequential and worrisome. Although Kennedy sometimes shies away from calling himself anti-vaccine, he is the founder of the anti-vaccine group Children’s Health Defense and once wrote a (now-retracted) magazine story on the (false) link between vaccines and autism. He’s called vaccines “a holocaust” and has claimed that “there’s no vaccine that is safe and effective.” A co-chair of the Trump-Vance transition team has said that Kennedy would be given access to federal health data in order to assess the safety of vaccines.

Though school vaccine requirements are determined by states, a prominent national-health figure casting doubt on vaccines’ safety can influence both state policy and individual parents’ decisions to vaccinate. If vaccination rates do drop, among the diseases that health experts worry will return is measles, the most contagious of the vaccine-preventable diseases.

A person infected with measles is most contagious right before they develop symptoms. They can infect others simply by sharing their air space; tiny droplets infected with measles can hang in the air for two hours “like a ghost,” Paul Offit, the director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, told me.

Kids with measles are sick and miserable. They’re photophobic—afraid of the light—and may struggle to breathe. Before the measles vaccine came along in 1963, 48,000 people were hospitalized with measles each year in America, many with pneumonia or inflammation of the brain. Five hundred of them died each year. When Samoa suffered a measles outbreak in 2019, 83 people died, out of a population of just 200,000.

Measles can also weaken the immune system, Matthew Ferrari, a biology professor at Penn State, told me. For two to three years after contracting measles, you’re likely to be hit harder by flu and other viruses. In rare cases, measles can cause a chronic form of brain inflammation that leads to a gradual loss of mental faculties and motor skills, and eventually, death.

[John Hendrickson: The first MAGA Democrat]

Measles is such a menace, in fact, that giving people “a choice” about whether to vaccinate their kids, as Kennedy often suggests, is not sufficient. People who have received two doses of the MMR vaccine are 97 percent protected against measles. But about 9 million people, including kids who are undergoing chemotherapy or who are on some kinds of immunosuppressants, can’t get vaccinated. These individuals rely on herd immunity from other vaccinated people, and when more than 5 percent of people choose not to be vaccinated, herd immunity suffers.

“Is it your right to catch and transmit a potentially fatal infection? No, it’s not,” Offit said. “You are part of this society, and you have to recognize that what you do affects other people.” Offit told me he’s already talked with pediatricians who say parents are hesitant to get their children vaccinated because of what they’ve heard Kennedy say.

Of course, there is a way to prevent Kennedy from having this much influence over public health: The Senate could reject his nomination. But that would require Republicans to stand up to Trump, which is a wild idea in itself.

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Robert F. Kennedy Jr., the nominee to be the next secretary of Health and Human Services, is America’s most prominent vaccine skeptic. An advocacy organization that he founded and chaired has called the nation’s declining child-immunization rates “good news,” and referred to parents’ lingering doubts about routine shots as COVID-19’s “silver lining.” Now Kennedy may soon be overseeing the cluster of federal agencies that license and recommend vaccines, as well as the multibillion-dollar program that covers the immunization of almost half the nation’s children.

Which is to say that America’s most prominent vaccine skeptic could have the power to upend, derail, or otherwise louse up a cornerstone of public health. Raising U.S. vaccination rates to where they are today took decades of investment: In 1991, for example, just 82 percent of toddlers were getting measles shots; by 2019, that number had increased to 92 percent. The first Trump administration actually presided over the historic high point for the nation’s immunization services; now the second may be focused on promoting vaccines’ alleged hidden harms. Kennedy has said that he doesn’t want to take any shots away, but even if he were to emphasize “choice,” his leadership would be a daunting test of Americans’ commitment to vaccines.

In many ways, the situation is unprecedented: No one with Kennedy’s mix of inexperience and paranoid distrust has ever held the reins at HHS. He was trained as a lawyer and has no training in biostatistics or any other research bona fides—the sorts of qualifications you’d expect from someone credibly evaluating vaccine efficacy. But the post-pandemic era has already given rise to at least one smaller-scale experiment along these lines. In Florida, vaccine policies have been overseen since 2021 by another noted skeptic of the pharmaceutical industry, State Surgeon General Joseph Ladapo. (Kennedy has likened Ladapo to Galileo—yes, the astronomer who faced down the Roman Inquisition.) Under Ladapo’s direction, the state has aggressively resisted federal guidance on COVID-19 vaccination, and its department of health has twice advised Floridians not to get mRNA-based booster shots. “These vaccines are not appropriate for use in human beings,” Ladapo declared in January. His public-health contrarianism has also started spilling over into more routine immunization practices. Last winter, during an active measles outbreak at a Florida school, Ladapo abandoned standard practice and allowed unvaccinated children to attend class. He also seemed to make a point of not recommending measles shots for any kids who might have needed them.

Jeffrey Goldhagen, a pediatrics professor at the University of Florida and the former head of the Duval County health department, believes that this vaccine skepticism has had immense costs. “The deaths and suffering of thousands and thousands of Floridians” can be linked to Ladapo’s policies, he said, particularly regarding COVID shots. But in the years since Ladapo took office, Florida did not become an instant outlier in terms of COVID vaccination numbers, nor in terms of age-adjusted rates of death from COVID. And so far at least, the state’s performance on other immunization metrics is not far off from the rest of America’s. That doesn’t mean Florida’s numbers are good: Among the state’s kindergarteners, routine-vaccination rates have dropped from 93.3 percent for the kids who entered school in the fall of 2020 to 88.1 percent in 2023, and the rate at which kids are getting nonmedical exemptions from vaccine requirements went up from 2.7 to 4.5 percent over the same period. These changes elevate the risk of further outbreaks of measles, or of other infectious diseases that could end up killing children—but they’re not unique to Ladapo’s constituents. National statistics have been moving in the same direction. (To wit: The rate of nonmedical exemptions across the U.S. has gone up by about the same proportion as Florida’s.)

All of these disturbing trends may be tied to a growing suspicion of vaccines that was brought on during COVID and fanned by right-wing influencers. Or they could be a lingering effect of the widespread lapse in health care in 2020, during which time many young children were missing doses of vaccines. (Kids who entered public school in 2023 might still be catching up.)

In any case, other vaccination rates in Florida look pretty good. Under Ladapo, the state has actually been gaining on the nation as a whole in terms of flu shots for adults and holding its own on immunization for diphtheria, tetanus, and pertussis in toddlers. Even Ladapo’s outlandish choice last winter to allow unvaccinated kids back into a school with an active measles outbreak did not lead to any further cases of disease. In short, as I noted back in February, Ladapo’s anti-vaccine activism has had few, if any, clear effects. (Ladapo did not respond when I reached out to ask why his policies might have failed to sabotage the state’s vaccination rates.)

  

If Florida’s immunization rates have been resilient, then America’s may hold up even better in the years to come. That’s because the most important vaccine policies are made at the state and local levels, Rupali Limaye, a professor and scholar of health behavior at Johns Hopkins University, told me. Each state decides whether and how to mandate vaccines to school-age children, or during a pandemic. The states and localities are then responsible for giving out (or choosing not to give out) whichever vaccines are recommended, and sometimes paid for, by the federal government.  

But the existence of vaccine-skeptical leadership in Washington, and throughout the Republican Party, could still end up putting pressure on local decision makers, she continued, and could encourage policies that support parental choice at the expense of maximizing immunization rates. As a member of the Cabinet, Kennedy would also have a platform that he’s never had before, from which he can continue to spread untruths about vaccines. “If you start to give people more of a choice, and they are exposed to disinformation and misinformation, then there is that propensity of people to make decisions that are not based on evidence,” Limaye said. (According to The New York Times, many experts say they “worry most” about this aspect of Kennedy’s leadership.)

How much will this really matter, though? The mere prominence of Kennedy’s ideas may not do much to drive down vaccination rates on its own. Noel Brewer, a behavioral scientist and public-health professor at the UNC Gillings School of Global Public Health, told me that attempts to change people’s thoughts and feelings about vaccines are often futile; research shows that talking up the value of getting shots has little impact on behavior. By the same token, one might reasonably expect that talking down the value of vaccines (as Kennedy and Ladapo are wont to do) would be wasted effort too. “It may be that having a public figure talking about this has little effect,” Brewer said.

Indeed, much has been made of Kennedy’s apparent intervention during the 2019 measles crisis in Samoa. He arrived there for a visit in the middle of that year, not long after measles immunizations had been suspended, and children’s immunization rates had plummeted. (The crisis began when two babies died from a vaccine-related medical error in 2018.) Kennedy has been linked to the deadly measles outbreak in the months that followed, but if his presence really did give succor to the local anti-vaccine movement, that movement’s broader aims were frustrated: The government declared a state of emergency that fall, and soon the measles-vaccination rate had more than doubled.

As head of HHS, though, Kennedy would have direct control over the federal programs that do the sort of work that has been necessary in Samoa, and provide access to vaccines to those who need them most. For example, he’d oversee the agencies that pay for and administer Vaccines for Children, which distributes shots to children in every state. All the experts I spoke with warned that interference with this program could have serious consequences. Other potential actions, such as demanding further safety studies of vaccines and evidence reviews, could slow down decision making and delay the introduction of new vaccines.

Kennedy would also have a chance to influence the nation’s vaccine requirements for children, as well as its safety-and-monitoring system, at the highest levels. He’d be in charge of selecting members for the Advisory Committee on Immunization Practices, which makes recommendations on vaccines that are usually adopted by the states and result in standardized insurance coverage. He’d also oversee the head of the CDC, who in turn has the authority to overrule or amend individual ACIP recommendations.

Even if he’s not inclined to squelch any determinations outright, Kennedy’s goal of giving parents latitude might play out in other ways. Brewer, who is currently a voting member of ACIP (but emphasized that he was not speaking in that capacity), said that the committee can issue several different types of rulings, some of which roughly correspond to ACIP saying that Americans should rather than may get a certain vaccine. That distinction can be very consequential, Brewer said: Shots that are made “routine” by ACIP get prioritized in doctor’s offices, for instance, while those that are subject to “shared clinical decision-making” may be held for patients who ask for them specifically. Shifting the country’s vaccination program from a should to a may regime “would destroy uptake,” Brewer told me.

Those would seem to be the stakes. The case study of vaccine-skeptical governance that we have in Florida may not look so dire—at least in the specifics. But Kennedy’s ascendancy could be something more than that: He could steer the public-health establishment off the course that it’s been on for many years, and getting back to where we are today could take more years still.