RFK Jr. Anti-Vaccine Activism / Children's Health Defense (1998-present)

Introduction

Robert F. Kennedy Jr., an environmental lawyer and son of Senator Robert F. Kennedy who has served as US Secretary of Health and Human Services since February 2025, has been one of the most prominent and persistent promoters of vaccine-skeptical claims in the United States for more than two decades. His central claims — that childhood vaccines cause autism and that thimerosal (a mercury-containing preservative formerly used in some vaccines) is responsible for a range of neurological harms — derive from sources that have been systematically investigated and refuted by the scientific and medical communities.

Kennedy's 2025 confirmation as US Secretary of Health and Human Services elevated the stakes of these claims from fringe advocacy to active federal health policy, making the factual record more consequential than at any previous point.

The Wakefield Foundation

The vaccine-autism claim originates primarily with Andrew Wakefield, a British gastroenterologist who published a study in The Lancet in February 1998 claiming a novel link between the MMR (measles-mumps-rubella) vaccine and autism in twelve children. The study generated enormous media coverage and contributed to vaccine hesitancy in the UK and United States.

Investigative journalist Brian Deer's years-long investigation, set out in the BMJ in January 2011, documented that Wakefield had manipulated patient data, had been paid by a law firm seeking to sue vaccine manufacturers before the study was conducted, and had failed to disclose these financial relationships to The Lancet. The UK General Medical Council's Fitness to Practise Panel ruled against Wakefield on 28 January 2010, and The Lancet retracted the paper in full in February 2010, saying that the claims in the original paper that the children were "consecutively referred" and that the investigations were "approved" by the local ethics committee "have been proven to be false". The GMC struck Wakefield off the medical register in May 2010, and in January 2011 the BMJ's editors concluded that the paper was fraudulent. He is no longer licensed to practise medicine in the UK.

Large studies since then have found no link between the MMR vaccine and autism. A Danish cohort study of 537,303 children (Madsen et al., New England Journal of Medicine, 2002) found no association (relative risk of autistic disorder in vaccinated versus unvaccinated children 0.92, 95% confidence interval 0.68 to 1.24). A 2019 Danish cohort study of 657,461 children (Hviid et al., Annals of Internal Medicine) likewise found no increased risk (fully adjusted hazard ratio 0.93, 95% confidence interval 0.85 to 1.02), including in children with a sibling history of autism or other autism risk factors.

The Thimerosal Hypothesis

Kennedy's specific contribution to vaccine-skeptical advocacy focused on thimerosal, an ethylmercury-containing preservative used in some multi-dose vaccine vials. In 2005 he published a widely-circulated article in Rolling Stone and Salon (later substantially corrected and ultimately retracted by Salon) claiming a government cover-up of the vaccine-mercury connection.

The thimerosal hypothesis was addressed by the 2004 Institute of Medicine (IOM) report, whose committee reviewed the published and unpublished epidemiological studies and found that the body of epidemiological evidence "favors rejection of a causal relationship between thimerosal-containing vaccines and autism". The Danish cohort study by Hviid et al. (2003, JAMA), following 467,450 children born in Denmark between 1990 and 1996, found no significant difference in autism risk between children vaccinated with a thimerosal-containing vaccine and children vaccinated with a thimerosal-free formulation of the same vaccine, and no dose-response association.

Thimerosal was removed from routine childhood vaccines in the United States by 2001 as a precautionary measure. Autism diagnosis rates continued to rise after its removal, which does not fit the prediction that thimerosal removal would reduce autism incidence.

Children's Health Defense

Kennedy founded the World Mercury Project in 2016, renamed Children's Health Defense (CHD) in 2018. CHD operates as a 501(c)(3) non-profit promoting vaccine-skeptical content and funding legal challenges to vaccine mandates. Reuters investigations published in February and August 2024 reported on CHD's finances, including substantial revenue growth during the COVID-19 pandemic, its fundraising methods, and the relationship between CHD's advocacy and Kennedy's political activities.

Policy Consequences

Kennedy was nominated as HHS Secretary in November 2024 and confirmed by the Senate on February 13, 2025, by 52 votes to 48 (AP). None of the actions below changes the epidemiological record summarised above.

• May 27, 2025, COVID-19 vaccines: Kennedy announced in a video on X that COVID-19 vaccines were no longer recommended for healthy children and pregnant women (AP).
• 2025, ACIP and thimerosal: Months after his confirmation, Kennedy removed all 17 members of the CDC's Advisory Committee on Immunization Practices (CBS News). At the reconstituted committee's June 25-26 meeting, members voted 5-1-1 to recommend that influenza vaccines be free of the preservative thimerosal, and Kennedy signed the recommendation on July 23, 2025. A CDC briefing document found that 96% of US influenza vaccines in the 2024-2025 season were already thimerosal-free (Healthcare Purchasing News).
• November 19, 2025, CDC autism page: The CDC's "Autism and Vaccines" page was rewritten to say that the claim "vaccines do not cause autism" is "not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism." The AP reported that the updated page does not cite any new research, and the president of the American Academy of Pediatrics said the conclusion that vaccines do not cause autism is "clear and unambiguous". The page keeps the headline "Vaccines do not cause autism" with an asterisk; Disability Scoop reported in July 2026 that an update had replaced a note citing an agreement with the Senate health committee chair with the statement "Scientists have not identified the root causes of autism."
• January 5, 2026, childhood schedule: HHS and the CDC cut the number of diseases for which vaccination is routinely recommended for all children to 11 (reports gave the previous figure as 17 or 18).
• March 16, 2026, court order: In a suit brought by the American Academy of Pediatrics and other medical groups, US District Judge Brian Murphy in Boston granted an injunction that halted the memo enacting the new schedule, the appointments of 13 new ACIP members and all votes taken by them. He found that the government had "bypassed" ACIP and that Kennedy's moves violated federal law (CBS News). HHS said it looked forward to the decision being overturned. The administration appealed, and the US Court of Appeals for the First Circuit heard argument on October 6, 2026 (Reuters). No appeals-court decision had been reported as of November 3, 2026.
• August 2026, autism research: KFF Health News reported on August 17, 2026 that Kennedy and his allies had passed a deadline for definitive answers on the causes of autism and that the effort had failed to produce evidence linking vaccinations to the disorder; NIH had issued about $50 million in autism research grants, most not due to finish for several years.
• September 17, 2026, Children's Health Defense conference: Kennedy gave the keynote at the conference of the group he once chaired, his first appearance there since becoming Secretary. Andrew Wakefield spoke after him (AP).

The scientific record on vaccine safety does not support the claims Kennedy has promoted, and public health bodies internationally have maintained consistent positions on vaccine efficacy and safety.

Verdict

Debunked. The vaccine-autism claim originated in a retracted 1998 paper whose lead author was struck off the UK medical register. The thimerosal-mercury hypothesis was addressed by the 2004 IOM report and multiple large-scale epidemiological studies, none of which found a causal link. Large Danish cohorts have since found no increased autism risk after MMR vaccination (n=657,461) and no increased risk of autoimmune, allergic or neurodevelopmental disorders after aluminum-containing vaccines (n=1,224,176). Autism diagnoses kept rising after thimerosal was removed from routine childhood vaccines, which does not fit the prediction that removal would reduce autism incidence. The 2025-2026 HHS and CDC actions described above changed official US messaging and policy, but the rewritten CDC autism page cites no new research (AP) and HHS's autism research had not, by August 2026, produced evidence linking vaccines to autism (KFF Health News). The scientific consensus on vaccine safety is not in dispute within the mainstream medical and epidemiological communities.

What Would Change Our Verdict

• A large-scale, pre-registered, independently replicated epidemiological study finding a causal link between MMR vaccination and autism
• Credible evidence of systematic suppression of data in the studies relied upon by regulatory bodies
• A mechanism plausibly linking aluminium adjuvants or other vaccine components to neurological harm at doses used in childhood immunisation schedules

Claims Made While Serving as HHS Secretary

Robert F. Kennedy Jr. was confirmed as U.S. Secretary of Health and Human Services on February 13, 2025. His tenure has produced a documented record of specific, attributable claims about vaccines that extends the pre-2025 record described above. Each is examined here against the available evidence, using his own words and actions rather than characterizations of his motives.

"Between 69 and 92 vaccines" — the dose-count claim

At a Senate Finance Committee hearing on September 4, 2025, Kennedy told lawmakers: "When I was a kid, I got three vaccines. I was fully compliant. Today's children have to get between 69 and 92 vaccines in order to be fully compliant." The figure echoes his 2021 book The Real Anthony Fauci, which stated that American children are "serving as pincushions for 69 mandated vaccine doses by age 18 — none of them properly safety tested."

The rebuttal: ABC News reported that medical experts put the actual figure at roughly 30 vaccine injections before age 18, excluding annual flu and COVID-19 shots — under half of Kennedy's lower number. The gap arises because Kennedy's count conflates individual disease-antigen exposures with injections: combination vaccines such as MMR deliver protection against three diseases in a single shot, and repeated annual flu doses are counted as if they were part of a fixed one-time schedule. Every vaccine on the CDC schedule undergoes FDA-reviewed pre-licensure clinical trials plus ongoing post-licensure surveillance through VAERS and the Vaccine Safety Datalink, and the National Academies' 2013 review of the cumulative childhood immunization schedule found no evidence that its overall scope is unsafe. Pediatric immunologist Dr. Pia Pannaraj told ABC News that children are naturally "exposed to 2,000 to 6,000 antigens every day" through ordinary contact with food and their environment, far exceeding the antigen load in the entire vaccine schedule.

The race-based vaccine schedule and the "336%" claim

At his second Senate confirmation hearing on January 30, 2025, Senator Angela Alsobrooks (D-Md.) questioned Kennedy about a 2021 statement in which he said "we should not be giving Black people the same vaccine schedule that's given to whites because their immune system is better than ours." Kennedy defended the remark by citing research from Mayo Clinic vaccinologist Dr. Gregory Poland on differing antibody responses by ethnicity, and separately cited a study claiming Black boys who received the MMR vaccine on the CDC-recommended schedule had a 336% higher risk of autism than those vaccinated later.

The rebuttal: FactCheck.org found neither citation supported Kennedy's claim. Dr. Poland's research examined differences in antibody titers to specific antigens, not overall immune competence or dosing needs; Poland stated his work was being "distorted," clarifying: "We do not have a study that shows African Americans need half the dose." The MMR-autism figure came from a 2014 reanalysis of CDC data by Brian Hooker, published in the journal Translational Neurodegeneration. That paper was formally retracted two months after publication because Hooker had undeclared competing interests — he was a paid consultant in vaccine-injury litigation — and post-publication peer review found his statistical methods invalid for the case-control dataset he analyzed as a cohort.

The aluminum-adjuvant campaign

Kennedy has claimed aluminum adjuvants used in vaccines are neurotoxic and responsible for autism, asthma, autoimmune disease, and food allergies, and as HHS Secretary he ordered a federal review of vaccine ingredients naming aluminum a priority concern. In July 2025, a large Danish cohort study of 1,224,176 children born between 1997 and 2018, with epidemiologist Anders Hviid of the Statens Serum Institut as senior author, was published in Annals of Internal Medicine; it found that cumulative aluminum exposure from vaccination in the first two years of life was not associated with increased rates of any of the 50 chronic disorders assessed, including autoimmune, atopic or allergic, and neurodevelopmental disorders. On August 1, 2025, Kennedy published an opinion piece on TrialSite News calling the study "a deceitful propaganda stunt" and called for its retraction, arguing that it excluded children who died before age two and did not compare vaccinated with unvaccinated children.

The rebuttal: The journal declined the retraction request on August 11, 2025. Editor-in-Chief Christine Laine stated that "retraction is warranted only when serious errors invalidate findings or there is documented scientific misconduct, neither of which occurred here." This was not the first such review: the World Health Organization's Global Advisory Committee on Vaccine Safety examined an earlier body of aluminum-autism research in 2012 and found it "seriously flawed," citing inappropriate study designs and questionable data. Infants absorb only a small fraction of their total aluminum exposure from vaccines compared with breast milk, formula, and food over the same period, and the only well-documented adverse reaction to aluminum adjuvants is localized injection-site irritation, not systemic disease.

The 2026 MMR-splitting claim

Following an August 10, 2026 executive order from President Trump directing officials to pursue single-antigen alternatives to combination vaccines, Kennedy said in a CNN interview aired August 15, 2026 that "a recent study that just came out ... very strongly supports the president," describing it as a meta-review linking the timing of the "autism epidemic" to combination vaccines and suggesting the CDC's own guidance was "probably outdated."

The rebuttal: FactCheck.org could find no such peer-reviewed study on PubMed. The paper Kennedy appeared to reference was published in a non-indexed outlet called the "Journal of Independent Medicine," co-authored by Andrew Wakefield — the physician struck off the UK medical register in 2010 over the retracted 1998 Lancet study described elsewhere in this entry. A legitimate study published the previous month, examining 2.5 million American children, found no MMR-autism association, directly contradicting Kennedy's characterization of the evidence. Single-antigen measles, mumps, and rubella vaccines have not been manufactured or licensed for use in the United States for nearly two decades.

The Samoa precedent

Before his HHS tenure, Kennedy traveled to Samoa in 2019. During his 2025 confirmation hearings he told Senators Ron Wyden and Ed Markey that the trip had "nothing to do with vaccines" and was intended to help digitize the country's health records. A January 20, 2019 letter Kennedy sent to then-Prime Minister Tuilaepa Sailele Malielegaoi, obtained by journalists and reported in August 2026, used the word "vaccine" or "vaccination" eight times and requested a "detailed health informatics assessment" of Samoa's MMR vaccine program. Months after Kennedy's visit, amid a period of depressed vaccination coverage, Samoa suffered a measles outbreak that killed 83 people, the large majority of them children under five.

The rebuttal: The Associated Press, which reported on the letter in August 2026, described it as contradicting Kennedy's confirmation-hearing testimony, which AP noted was not given under oath. HHS told AP the visit "was unrelated to vaccines" and rejected any claim that Kennedy lied to Congress. This is not itself a scientific dispute; it is included because it bears on the reliability of Kennedy's public statements about his own vaccine-related activities, which is relevant context for evaluating his other claims.

Financial interests in vaccine litigation

Kennedy has for years served as an attorney affiliated with the law firm Wisner Baum in product-liability litigation against Merck over its Gardasil HPV vaccine, which the suits allege caused neurological and autoimmune injuries. Ahead of his confirmation, Kennedy disclosed to HHS ethics officials that he would retain the right to 10% of any referral fees recovered in the litigation even after taking office, rather than fully divesting.

The rebuttal: Gardasil has been extensively studied in large post-licensure surveillance programs, which have not substantiated a causal link between the vaccine and the autoimmune conditions alleged in the litigation; the CDC and WHO continue to recommend HPV vaccination based on its demonstrated reduction in HPV-related cancers. The financial relationship is documented here as a disclosed conflict of interest relevant to assessing Kennedy's public statements on this specific vaccine, not as evidence about vaccine safety itself.

The "CDC whistleblower" narrative

Kennedy wrote the foreword to the 2017 book Vaccine Whistleblower: Exposing Autism Research Fraud at the CDC by Kevin Barry, which presents recordings of CDC scientist William Thompson discussing statistical choices made in a 2004 Pediatrics study on MMR timing and autism. Children's Health Defense has continued to promote the claim that CDC leadership ordered the destruction of data showing a vaccine-autism link in Black boys.

The rebuttal: The 2004 study itself found no significant overall association between MMR timing and autism. Thompson's disclosures concerned a subgroup analysis that Hooker later used — without disclosing his own financial conflict — in the paper that was retracted for the reasons described above. No independent government, congressional, or journalistic investigation has substantiated a CDC cover-up of a genuine autism-MMR link. Large independent cohorts, including Hviid et al.'s 2019 Danish study of 657,461 children and Taylor et al.'s 2014 meta-analysis spanning more than 1.2 million children, have since found no MMR-autism association in any subgroup, including children with a sibling history of autism.

What the Evidence Actually Shows

Across two decades, Kennedy's specific vaccine-safety claims — the size of the childhood schedule, aluminum adjuvants, race-differentiated dosing, MMR splitting, and the CDC cover-up narrative — share a common pattern: each rests on a study that is retracted, methodologically discredited, published outside indexed peer review, or authored by figures with undisclosed financial interests in the outcome, set against large, independently replicated, peer-reviewed cohort studies and meta-analyses spanning millions of children that find no such associations. His post-2025 record as HHS Secretary — the ACIP overhaul, the demand to retract a Danish aluminum safety study, and the discrepancy AP reported between his Samoa testimony and his own 2019 letter — is examined here not to characterize Kennedy personally, but because it is the record against which his specific anti-vaccine claims continue to be assessed while he holds the nation's senior public health office.