But Ladapo’s recommendation — extrapolated from a short state analysis that has not been peer-reviewed, carries no authors and warns that its findings are “preliminary” and “should be interpreted with caution” — was swiftly condemned by medical and public health leaders, who said the Florida surgeon general’s announcement was politics masquerading as science and could lead Americans to forgo lifesaving interventions.

More than a dozen experts interviewed by The Washington Post — including specialists in vaccines, patient safety and study design — listed concerns with Florida’s analysis, saying it relies on information gleaned from frequently inaccurate death certificates rather than medical records, skews the results by trying to exclude anyone with covid-19 or a covid-related death, and draws conclusions from a total of 20 cardiac-related deaths in men 18-to-39 that occurred within four weeks of vaccination. Experts noted the deaths might have been caused by other factors, including underlying illnesses or undetected covid.

“We’re talking about a very small number of deaths. An extra death or two would potentially change these results,” said Robert Wachter, chair of the department of medicine at the University of California at San Francisco and co-author of a patient-safety textbook used in many medical schools. “I’m hesitant to even call it a paper; it isn’t published anywhere. The idea that [the analysis] … is being used to change policy — it does not have the scientific chops to do that.”

“If you submitted that to a peer-reviewed journal, unless you were paying them to publish it, it would get rejected,” added Daniel Salmon, who leads the Institute of Vaccine Safety at Johns Hopkins Bloomberg School of Public Health. He called Florida’s report “a dangerous thing to do.”

Twitter briefly removed Ladapo’s post touting the study over the weekend, citing it as misinformation, before restoring it hours later; the tweet has since been shared more than 50,000 times, cheered by anti-vaccine advocates and amplified by conservative media highlighting Ladapo’s claim that his state will “not be silent on the truth.”

The firestorm has put a spotlight on Ladapo, a Harvard-trained physician and researcher who had not specialized in infectious disease but rose to prominence after writing a number of op-eds in the Wall Street Journal questioning coronavirus vaccines, mask-wearing and other interventions. The columns caught the attention of Florida Gov. Ron DeSantis (R), who late last summer offered Ladapo the job of overseeing a roughly 15,000-person health department in the nation’s third-most-populous state.

As surgeon general, Ladapo’s efforts to discourage parents from getting their children vaccinated, challenge mask mandates and oppose gender dysphoria treatments for children have been opposed by medical associations, such as the Florida chapter of the American Academy of Pediatrics. Those stances have also won accolades from conservatives and helped the governor burnish his credentials as a populist conservative as he runs for reelection and positions himself for the 2024 GOP presidential contest.

Kids’ coronavirus vaccines are hard to find in Fla. Many blame DeSantis.

In an interview Monday, Ladapo defended the vaccine study as an overdue effort to investigate risks associated with the vaccines. He has argued that high levels of immunity to the virus raise fresh questions about the shots’ risks versus benefits. The Florida analysis sought to explore the relationship between the shots and cardiac-related deaths, as well as deaths from all causes, by examining the death certificates of Florida residents 18 and older who died within 25-weeks of vaccination between December 2020 and June 2022.

“This should have been done by anyone who had the ability to do it, in terms of the data and the technical expertise,” Ladapo said.

Ladapo declined to name who worked on the analysis — saying that was a “fake issue” — and suggested it did not need to be submitted to a journal or go through peer review. “The point of this analysis was to look at a question that was important to answer,” he said.

In fact, the link between conditions known as myocarditis and pericarditis, which are types of heart inflammation, and the messenger RNA coronavirus vaccines has been and continues to be heavily researched across several continents.

“We’ve all been asking these questions,” said Peter Marks, the top vaccine official at the Food and Drug Administration. “We already know that myocarditis and pericarditis are somewhat increased in younger males who get the vaccine, but we also know that it’s far outweighed by the benefits.”

Salmon, who previously oversaw vaccine safety for the federal government’s National Vaccine Program Office, agreed that there are real, but rare, heart risks associated with the vaccines — an issue he knows well because he is leading a global study of it.

But Salmon said he would still recommend the vaccines for adult men under 40, including for his two sons in that age group. “The vaccines are not perfect, but the benefits still outweigh the risks,” he said.

Both the FDA and the Centers for Disease Control and Prevention have said the vaccines can cause heart inflammation in rare cases, but the symptoms are temporary, with cases generally resolved within hours or days. Large-scale observational studies on hundreds of millions of vaccine recipients have shown that while heart inflammation can be a rare side effect of the messenger RNA vaccines that disproportionately affect young men, the small number of deaths in that age group and protective effects of the vaccines at preventing severe covid, outweigh those risks.

Ladapo told The Post that he hoped his mentors at Harvard, such as health economist David Cutler, would support the methods used in Florida’s study. But reached by phone Monday evening, Cutler criticized the vaccine study as deeply flawed, and said he worried it would discourage people who could benefit from the shots.

Cutler said he was proud of Ladapo’s work as a student and supported his inquisitiveness, including his initial Wall Street Journal essays raising questions about the long-term risks of lockdowns, and more recently, his efforts to probe whether vaccines might cause harms. “We should never be afraid of asking questions, no matter how strong the received wisdom,” he said.

But Cutler said Florida’s vaccine study had severe methodological problems.

“If I was a reviewer at a journal, I would recommend rejecting it,” Cutler said, adding that Ladapo was wrong to base Florida’s vaccine policy on it.

“Anytime you tell people to do something incorrect, you risk causing harm,” Cutler added, saying the Florida surgeon general has increasingly staked out positions on vaccines and other public health issues that aren’t backed by rigorous data. “Some of his statements have become more strident than the evidence warrants.”

Ladapo’s positions have won him a growing following in conservative circles, however, particularly his claims that doctors are “indoctrinated” about vaccines in medical school and that “greed” is motivating them to recommend shots for many conditions.

“I never thought I would listen to a surgeon general of any kind, and certainly not a state surgeon general, and then all of a sudden, out of nowhere, you appear,” Fox News host Tucker Carlson said in May, when hosting Ladapo for a nearly hour-long conversation on his daytime talk show. “I think a lot of people — I’m speaking, for myself for sure — believe you much more than health authorities that we hear in Washington.”

“More than the surgeon general of the country, I hope so,” Ladapo responded, chuckling. “Only one of these two is telling the truth.”

Ladapo’s path to Florida

Born in Nigeria before moving to the United States as a young child, Ladapo became a star athlete who ran track at Wake Forest University, then went to Harvard for a joint medical degree and PhD.

In 2008, Ladapo told a Harvard publication he felt lucky “to have been here and able to benefit and grow in this tremendously rich environment.”

But he was already wrestling with some of the questions that now define his career. “One day, I think we will look back and be amazed at the crudeness of the methods we once used to make decisions about our patients’ lives,” Ladapo wrote in 2010 as a second-year medical resident.

After leaving Harvard, he took jobs first at New York University and then, the University of California at Los Angeles, where he became a tenured professor and mostly focused on research, winning multiple federal grants while still seeing patients about one day a week.

Ladapo took some traditionally liberal positions in those years, posting on Facebook that he had signed petitions in 2016 criticizing the media for using terms like “alt-right” and “nationalism” instead of “White supremacist.” He also urged Republicans not to repeal the Affordable Care Act in 2017 and decried the Trump administration’s efforts to separate migrant families at the border in 2018.

“Access to basic care is something every human should have,” Ladapo wrote on Facebook in 2017, as doctors mobilized to fight ACA repeal.

Five people who had collaborated closely with Ladapo on research said he had seemed on a similar path as many of his colleagues, if more willing to embrace contrarian positions in staff debates, before his abrupt right turn in 2020 that several described as “mystifying” and a “conundrum.”

“His work over the pandemic is really shocking to me,” said one person who worked closely with Ladapo on multiple research studies, and like others interviewed, spoke on the condition of anonymity for fear of being targeted by anti-vaccine groups.

In his memoir, “Transcend Fear,” published in August, Ladapo offers clues to his professional transformation, writing that he spent decades grappling with personal trauma linked to memories of being sexually abused by a babysitter as a young child. He said his journey overcoming that experience empowered him to see medicine in a new light and to challenge its orthodoxies.

Ladapo credits several days of therapy in December 2019 with Christopher Maher, a former Navy SEAL, with freeing him of the anxiety linked to his abuse and making him “literally a new man” — just in time to face the pandemic, he says.

“Maybe I would have been one of those ‘the end justifies the means’ doctors had I not worked with Christopher Maher and rid myself of the fear that was compromising my judgment,” Ladapo writes.

Ladapo also says that as he continued to pen Wall Street Journal op-eds and criticize pandemic policies — joining groups like America’s Frontline Doctors that were pushing hydroxychloroquine as a covid treatment in July 2020 despite warnings from experts that it didn’t work — he was ostracized at UCLA, with some colleagues refusing to work with him.

His supervisor at UCLA later told Florida agents conducting a background check on Ladapo that she would not recommend him for state surgeon general, citing his decision-making, the Orlando Sentinel first reported.

UCLA declined to comment.

In Monday’s interview, Ladapo acknowledged that his beliefs evolved over time, and he suggested that the political climate — and the powerful responses to the pandemic — had made it harder to hold nuanced positions.

“There’s no space for people to have different ideas,” he said, adding that the medical field’s hostility to those raising questions about coronavirus vaccines “gradually opened me up to seeing that more was going on than just objective evaluation.”

Vaccine disinformation has had real-world effects on Americans who have been confused or frightened by reports they may be unsafe, researchers say.

Jason Schwartz, a Yale University associate professor who specializes in vaccine policy, co-authored a study released last month that found “substantially higher excess death rates for registered Republicans when compared to registered Democrats, with almost all of the difference concentrated in the period after vaccines were widely available in our study states.”

He argued that Florida’s analysis appeared part of a “relentless effort … to sow confusion and undermine the public health response.”

Other experts also worried that Ladapo’s warning would hamper efforts to encourage millions of people to get coronavirus booster shots before a predicted fall and winter surge of cases.

Few Americans get new covid booster shot ahead of projected winter surge

“People in the public go, ‘Wow, a government report shows that vaccines are dangerous.’ It’s going to scare people,” Salmon said.

Biden officials, initially blindsided by Florida’s warning, spent the weekend deliberating about how and even whether to respond, according to four people with knowledge of the conversations who spoke on the condition of anonymity because they were not authorized to comment. White House and health department leaders worried that, if unanswered, Ladapo’s message would inflame vaccine fears — but they were also concerned that attempting to rebut him would amplify his message.

“We do take very carefully, and we debate very closely, whether or not it’s the right thing to give attention to something like this,” said the FDA’s Marks.

By Monday, federal officials had crafted a statement that called Florida’s recommendation “flawed and a far cry from the science,” Sarah Lovenheim, spokesperson for the Department of Health and Human Services, wrote in an email. “COVID-19 vaccines have been proven safe and effective, and severe adverse reactions are rare. The benefits of COVID-19 vaccination — preventing death and hospitalization — are well-established and continue to outweigh any potential risks.”

Florida’s study also arrived as White House leaders were pushing their own vaccine message. Earlier that same day, Biden health officials had trumpeted study findings showing the shots resulted in about 675,000 fewer hospitalizations and about 350,000 fewer deaths among seniors last year.