How CDC nominee Dave Weldon’s support for anti-vaccine theories runs long and deep 

MELBOURNE, Fla. — Unlike President Trump’s picks to lead other health agencies who established their conservative bona fides during the Covid-19 pandemic, his choice to head the Centers for Disease Control and Prevention, Dave Weldon, was virtually invisible during that period.

But an examination by STAT of thousands of pages of documents from Weldon’s 14 years in Congress, part of his archives housed here at the Florida Institute of Technology, and interviews with a half-dozen former health officials, found that his support for anti-vaccine theories runs long and deep. His advocacy of these views goes back decades, even longer than those of Robert F. Kennedy Jr., the secretary of Health and Human Services.

That steadfast history may explain why Trump selected him to run an agency in which he would oversee vaccine policy and messaging. His name rose to the top of the administration’s short list for CDC directors after a push from Kennedy’s team, three people familiar with the process told STAT.

Weldon is a physician who served in Congress from 1995 until 2009, and has kept a low profile since. After a failed Senate run in 2012, the longtime vaccine critic and anti-abortion advocate settled back into practicing medicine in the relatively quiet coastal Florida town of Melbourne. He joined the faculty of Melbourne’s flagship institution, the Florida Institute of Technology, for its nascent biomedical engineering program. He was, seemingly, out of the political circus.

So when President Trump announced last November that he’d tapped Weldon to lead the CDC, it took even some Republicans by surprise. 

But among those who have questioned vaccine safety, Weldon is an important voice. The documents examined by STAT show how the former representative’s theories about vaccines and autism grew in the early 2000s, and the building pushback he received from health officials and the scientific community. The documents also chronicle Weldon’s longtime interest in HIV/AIDS and reproductive care policy, shaped starkly by his religious views.

On Thursday, Weldon will be the first CDC nominee to face the Senate confirmation process, a new requirement implemented in 2023. He will appear before the Senate HELP Committee, which will grill Weldon on his health care stances before voting to advance his nomination. The former congressman will face myriad questions about the agency’s future, his long, documented past as a vaccine critic, and his ideological approach to reproductive and sexual health.

The former congressman’s archives indicate that while the broader scientific community moved away from vaccine theories, fears about vaccines and autism, and since-retracted studies that sought to prove a link, Weldon’s position was not swayed. 

While Weldon’s support for anti-vaccine theories is more clinical than passionate, it is unmistakable in his writings over the years. “When evaluating whether or not to vaccinate their children against influenza, parents should not be forced to choose between the risk of the mercury containing preservative thimerosal-whether real or perceived and the risk of contracting influenza,” Weldon wrote to the House Appropriations chair in 2007. (The CDC website notes that thimerosal was never in MMR vaccines, but is in some multidose formulations of flu shots). 

In March 2004, ten of the 13 researchers on a now-infamous study by Andrew Wakefield, which in 1998 linked autism to MMR vaccines and sparked a broad panic about vaccine safety, issued a retraction. The Lancet, which published the study, had renounced it a month earlier, citing study concerns and Wakefield’s funding by a project aimed at a legal case for parents of children with vaccine injuries.

That July, Weldon appealed to the head of the House Appropriations Committee to fund an autism research center led by Wakefield. He requested $1.9 million in the 2005 budget for the Austin-based Thoughtful House, a clinic and research hub that would study “the biological origins” of childhood development disorders including autism. The center did not receive congressional funding. In 2010, facing mounting scrutiny over his research and the loss of his medical license, Wakefield resigned from Thoughtful House. 

Weldon said in multiple letters to top health officials during his time in Congress that he supported childhood vaccinations, but questioned the CDC’s objectivity in assessing immunizations’ safety. Letters, memos and research in the congressman’s archives continued to push the theory that vaccines cause autism, even after a national board of scientists rejected the link in 2004. 

His 2007 proposal to ban thimerosal from vaccines, for instance, was “an attempt to err on the side of caution and stop the practice of injecting a known neuro-poison into infants,” he wrote to colleagues. Thimerosal was removed from all childhood vaccines in the U.S. in 2001.

Weldon’s long criticism of vaccines, even as evidence mounted for their safety, has many current and former CDC officials on edge. 

“He held on to this false belief that vaccines were harming our children. When you see that by people in positions of authority…He had a responsibility that he shirked,” said Richard Besser, president and CEO of the Robert Wood Foundation and a former CDC acting director. 

A new chapter for CDC 

Trump, when announcing Weldon as the CDC nominee last November, wrote on Truth Social that “Americans have lost trust in the CDC and in our Federal Health Authorities, who have engaged in censorship, data manipulation, and misinformation.” 

He nodded to the “Make America Healthy Again” movement in the post, continuing: “Given the current Chronic Health Crisis in our Country, the CDC must step up and correct past errors to focus on the Prevention of Disease.”

If confirmed as CDC director, Weldon would have a vast purview over vaccine policy, HIV/AIDS programs, and public health messaging about crises from the measles outbreak in Texas to the burgeoning spread of the H5N1 virus among livestock and the future of CDC’s public health outreach across states and localities. 

The CDC is under intense scrutiny from the Trump administration and the Elon Musk-led U.S. DOGE Service, which aims to slash costs across the federal government. The agency’s roughly $9 billion budget stands in the crosshairs of the administration’s cost-cutting plans; while that spending power has grown marginally through the past decade, congressional Republicans are increasingly critical of CDC’s vast mandate over public health messaging. House appropriators  aimed last year at slashing spending by more than 20% to focus the agency on “communicable diseases rather than social engineering.” Residual voter frustration over the Covid-19 response, combined with the MAHA movement spearheaded by Health and Human Services Secretary Robert F. Kennedy Jr., loom large over CDC’s future. 

There is also tension between Kennedy’s promise of “radical transparency” across health care agencies and the constant confusion about when that applies. Public meeting of agency advisors for the CDC and Food and Drug Administration have been cancelled or delayed; HHS recently moved to whittle down public comment on regulatory action; and there is still no clarity on how many health care federal workers were dismissed in mass layoffs, what work they did, or how many may return to their posts. 

Other Trump health care nominees have weathered questions about these shakeups, and remained largely noncommittal. But the nominee to lead the CDC may face the most pointed questioning: The agency is directly responding to a measles outbreak in West Texas that has killed one person and infected more than 200 others. (An individual in New Mexico, which is also trying to contain an outbreak, recently tested positive for measles after death.) Weldon, as director, would shape CDC’s messaging on vaccines, including the measles shot he questioned for years.   

Advocating abstinence

A review of Weldon’s archives showed a longtime physician who first began questioning vaccine safety in 1999, shortly after Wakefield’s study. He was also committed throughout the years to global HIV/AIDS programs, but pushed to see them centered in more faith-based messaging. 

A 2001 letter to Morton Kondracke, then executive editor of Roll Call, threaded together these views. Responding to an op-ed Kondracke had penned about Parkinson’s disease, Weldon griped that there was little funding for autism research compared to HIV/AIDS. 

“What is ironic for me in all this is that I took care of a lot of AIDS patients and I saw first hand the need for better treatments and research,” Weldon wrote. “It is a terrible disease, but it is behaviorally related. Nobody gets Parkinson’s or autism because of anything they did.”

That same year, Weldon fought to block same-sex marriage in the District of Columbia. That was the first time Carl Schmid, executive director of the HIV+Hepatitis Policy Institute, recalls encountering Weldon. 

“I hope he’s changed,” said Schmid. “How is he going to prevent HIV without outreach to the gay community and trans community and others?”

Weldon was “really committed” to global HIV/AIDS programs such as President George W. Bush’s PEPFAR initiative (funding for which the Trump administration suspended in January) said Schmid. “But he also was very ingrained in the abstinence-only message.”

That commitment to abstinence messaging is evident throughout documents of Weldon’s years in Congress. In a March 2001 letter to Helene Gayle, then-director of the National Center for HIV, STD and TB Prevention, Weldon and Rep. Mark Souder (R-Ind.) wrote that the CDC’s HIV guidelines included “extensive discussions” about reducing stigma around activities that place people at higher risk for HIV transmission. But, they continued, “It is our belief that, in many ways, our culture has actually stigmatized activities that do NOT increase HIV risk, such as abstinence and virginity.”

Weldon for years championed funding for abstinence-based sexual health programs and in 2003 traveled Uganda to explore their impact. He advocated in letters and memos after that trip for a faith-based coordinator on HIV/AIDS messaging in Africa, and an “ABC” approach to sexual health: “Abstain, Be faithful, or use Condoms.” Hundreds of pages of reports about abstinence programs are housed in Weldon’s archives. He regularly asked CDC about emphasizing abstinence in its messaging, whether through HIV/AIDS programs or the Division of Adolescent and School Health. 

“What are some activities that DASH has conducted to increase the sensitivity toward abstinence programs through its community partners?” read one handwritten note scrawled on top of an April 2003 press release for a recently launched HIV testing initiative at CDC. 

The shaping of Weldon’s vaccine views 

Weldon’s concerns about vaccines and autism surfaced soon after Wakefield’s since-retracted 1998 study positing a link between the measles, mumps and rubella shot and cases of autism. In a May 1999 letter to Jeffrey Koplan, then director of the CDC, Weldon cites Wakefield’s research and asks “Is there anyone at CDC attempting to independently duplicate his findings?”

In an April 2001 letter to Rep. Ralph Regula, then-chairman of the House appropriations subcommittee on health, Weldon wrote he was “pleased” to work with the group the previous year to include language directing the National Institutes of Health “to fully explore and attempt to duplicate research efforts of Dr. Andy Wakefield.”

In subsequent years, numerous studies published in medical journals and reports issued by national health advisors would find no link between the MMR vaccine and autism. 

Weldon nodded to some of this research in a December 2002 letter to Walt Larimore, vice president of the Christian-based organization Focus on the Family. 

“Since you and I last spoke about the autism issue, there have been several studies in the medical literature that seem to suggest the vaccines may be quite safe,” Weldon wrote. But those studies did not answer his biggest question, he wrote. “That fundamental question is: are there some cases of regressive autism that are due to the measles component of the MMR?”

Weldon continued: “I feel quite strongly that it is important that somebody, somewhere try to duplicate Dr. Wakefield’s findings. To date we have not seen that.”

Wakefield’s findings have not been replicated in the two decades since.

In 2016, Weldon appeared in Wakefield’s “Vaxxed,” a documentary purporting to show the link between MMR vaccines and autism, and a cover-up by federal health agencies. 

People on the national panel that reviewed vaccine safety, now known as the National Academies of Medicine, “bounce around” from industry to government and academia, Weldon said in the film. “It just didn’t seem to me like we were running a system that was credible.”

Revisiting the autism question

President Trump has convened a “Make America Healthy Again” commission, helmed by longtime vaccine critic RFK Jr. 

“Some of the possible factors we will investigate were formally taboo, or insufficiently scrutinized,” the health secretary said when he arrived at HHS headquarters last month. Among them: “The childhood vaccine schedule.”

Many senators including HELP Chairman Bill Cassidy (R-La.) have sought assurances from RFK Jr. and other top health officials that they will not erode vaccine confidence, or simply that they do not believe vaccines cause autism. RFK Jr. stopped short of endorsing that view.

“If you show me data, I will be the first person to assure the American people … that they need to take those vaccines,” he told Cassidy. The senator ultimately voted to confirm RFK Jr.

“I will use my authority as Senate committee chair to rebuff any attempt to remove the public’s access to lifesaving vaccines,” Cassidy said. “I will watch carefully for any effort to wrongfully sow any fear about vaccines.”

The CDC is currently planning a large-scale study of potential connections between vaccination and autism, according to a Reuters report. If confirmed, Weldon will oversee those efforts and the agency’s messaging on vaccines. 

In 2007, Weldon introduced a bill that would have removed vaccine review from the agency, establishing an independent health department to assess immunization recommendations. His move came after years of correspondence with then-CDC director Julie Gerberding — correspondence that started as conciliatory and friendly memos about autism research. 

But Weldon pushed back forcefully in January 2004, demanding that CDC delay a February meeting of the Institutes of Medicine and its officials about vaccine safety. 

“At present, I have lost confidence in the ability of officials at the CDC to give an honest evaluation of the matters at hand,” Weldon wrote. The agency exhibited a “clear bias towards building confidence in the safety of vaccines rather than providing an objective presentation of the data.”

Gerberding responded in a February 2004 letter that it was “extremely important to have the IOM conduct an objective review of emerging data when it has a bearing on vaccine safety as quickly as possible.” The meeting went forward. 

“From our conversations, I know we share a commitment to ensuring that vaccine safety monitoring and research is encouraged and adequately supported. I think we also agree that it should be done with integrity, be of high scientific quality, and have appropriate oversight. I believe that the vaccine safety monitoring at CDC meets these criteria,” Gerberding wrote in a subsequent, March 2004 letter to Weldon. 

Now, Weldon is set to oversee that agency’s vaccine monitoring himself. In the two decades since his questions to Gerberding and his efforts to take immunization reviews away from the agency, no one has replicated Wakefield’s findings. But vaccine hesitancy has grown, snowballing during the Covid-19 pandemic and culminating in an administration that has emphasized personal choice to get vaccinated amid an ongoing measles outbreak. 

That has longtime public health officials concerned about the agency’s future under Weldon’s leadership.

“I really hope that he will learn about the CDC and the current approaches to vaccine programs, vaccine safety, vaccine promotion, vaccine research, because the world is quite a bit different now than it was 20 years ago,” said Anne Schuchat, a retired, longtime CDC official who worked with Gerberding. 

Weldon’s congressional archives fill 21 gray filing boxes on the third floor of FIT’s modernist Evans library. FIT, locally called Florida Tech, is mostly known for its engineering and aeronautics programs, as Melbourne sits on Florida’s Space Coast and under the shadow of Cape Canaveral’s frequent rocket launches.

Weldon is familiar with the campus. Before joining the faculty — and later its board — he spoke at a 2009 dedication for the university’s autism center, for which he’d secured funding in his last year in Congress.

What caught his interest, he said then, was rising reports of autism in children, and a vast disparity between funding for autism research and diseases such as HIV/AIDS. But Weldon was also fresh out of Congress, with no imminent plans to return to Washington: “It’s great to be back with so many of you, and if you need a doctor, I’m seeing patients just down the road here,” he joked at the end of his speech.