2026 Measles Outbreak and Anti-Vaccine Misinformation Surge

The pivotal moment came on June 9, 2025, when HHS Secretary Robert F. Kennedy Jr. removed all 17 members of the Advisory Committee on Immunization Practices (ACIP) ^[5][19][28]. Kennedy justified the mass termination by saying the committee had "become little more than a rubber stamp for any vaccine" and that "a clean sweep is needed to re-establish public confidence in vaccine science" ^[5][19]. He also characterized the panel as plagued by conflicts of interest and staffed with late Biden-administration appointees ^[28].

The medical community responded with alarm. The American Medical Association said the action "undermines that trust and upends a transparent process that has saved countless lives" ^[19][5], while the American Academy of Pediatrics called it an "escalating effort by the Administration to silence independent medical expertise" ^[5]. Dr. Céline Gounder noted the irony on CBS News: sitting ACIP members "cannot own stock in or be on any kind of advisory board for pharmaceutical companies," while "Kennedy, on the other hand, is conflicted. He has sued multiple vaccine manufacturers" ^[5].

A Congressional Research Service tally documents what followed. COVID-19 vaccination for healthy children moved from a universal recommendation to "shared clinical decision-making" in May 2025; ACIP recommended against use of the combined MMRV vaccine in September 2025; the hepatitis B birth dose was shifted to shared decision-making for certain infants in December 2025; and in January 2026 RSV immunization was reclassified from all infants to certain high-risk groups ^[6]. A federal district court subsequently stayed most recommendation changes made after June 11, 2025, in an order issued March 16, 2026 — after this snapshot ^[6].

The ACIP firing and the schedule rollbacks are verified policy facts, not claims in dispute. Reporting that framed the changes as a single late-2025 removal of seven childhood vaccines overstates a rollback that actually happened in separate steps across 2025 and 2026 ^[6].

The false MMR-autism link traces directly to Andrew Wakefield's 1998 Lancet paper, which the journal fully retracted in a statement published February 2, 2010, saying it was clear that "several elements" of the paper were incorrect ^[11][12]. Investigative reporting by Brian Deer in the British Medical Journal established that the work was, in the words of the accompanying editorial, an "elaborate fraud" ^[13]. A British solicitor working on a lawsuit against the vaccine maker had paid Wakefield hundreds of thousands of pounds, and "three of 9 children who were reported in the paper to have regressive autism were not diagnosed with autism at all" ^[13]. Britain's General Medical Council censured Wakefield in January 2010 and he was later stripped of his British medical license ^[13][21]. A later review concluded Wakefield and colleagues "were guilty of deliberate fraud (they picked and chose data that suited their case; they falsified facts)" ^[12].

Despite that record, exposure to the myth remains near-universal. Kaiser Family Foundation polling conducted April 8–15, 2025 found that "about six in ten adults (63%) and parents (61%) say they have read or heard the false claim that the MMR vaccines have been proven to cause autism in children," while roughly one-third of adults had encountered the claim that the measles shot is more dangerous than the disease; 25% said the autism link was definitely or probably true and 19% said the same of the danger claim ^[9].

Exposure is broad, but KFF's own trend data does not show belief accelerating. In its May 2026 wave, KFF found 66% of adults had heard the autism claim and 29% the "more dangerous" claim, and reported "no notable changes in views of the long-standing myth that MMR vaccines cause autism," with belief in the danger claim steady since a 2024–2025 rise ^[10].

Research documents a spillover from COVID-19 vaccine politics to routine childhood immunizations. A study in the Harvard Kennedy School Misinformation Review found that "liberals in the United States hold less negative attitudes not only towards the COVID-19 vaccines compared to conservatives but also towards unrelated vaccines (influenza, MMR, HPV, chickenpox)," with conservatives' attitudes moving in the opposite direction across the same set of unrelated vaccines ^[16].

The spillover shows up in behavior. A JAMA Network Open study of roughly 322,000 children born between 2017 and 2023, reported by STAT News, found that babies who did not receive their vaccines on time at 2 months "were more than seven times more likely not to receive their first measles, mumps, and rubella (MMR) shot by age 2" ^[29]. National data tracks the same direction: kindergarten MMR coverage fell to 92.5% in the 2024–25 school year, down from 92.7% the year before and 95.2% in 2019–20 ^[3].

Attitude shifts have translated into missed appointments, and missed appointments into a coverage gap.

The outbreak is centered in northwestern Spartanburg County, South Carolina, where the state health department first reported cases in October 2025 ^[7][18][31]. By January 27, 2026, South Carolina had confirmed 789 cases — surpassing the 762-case Texas outbreak of 2025 to become the largest in the United States since measles was declared eliminated here in 2000 ^[7]. At that point 557 people were in quarantine, and the state reported exposures at three additional schools on top of existing quarantines among students at 20 others ^[7]. Earlier in January, with 700 cases confirmed, 485 people were in quarantine and 10 in isolation ^[31].

The outbreak kept growing. South Carolina reported 920 cases by February 6, 879 of them (96%) in Spartanburg County ^[8], and 950 cases by February 13 ^[24][1]. Cases in North Carolina, Washington and California have been linked to the South Carolina outbreak ^[7]; PBS NewsHour also reported spread to Ohio ^[18].

Nationally the spread was broad but concentrated. Twenty states had reported cases as of the February 6 CDC update ^[8], and a separate outbreak continued along the Arizona–Utah border ^[7]. Two new jurisdictions appeared in the February 12 update: an unvaccinated infant in New York and an adult in Washington County, Vermont, who became ill after international travel ^[1].

The data show the outbreak concentrated among the unvaccinated. In the CDC update covering the 733 cases confirmed by February 6, 2026, 95% of patients were unvaccinated or had unknown vaccination status and 4% were fully vaccinated ^[8]. A week earlier, at 588 cases, the figure was 93% ^[20]. In South Carolina, the vaccination status of 94% of the state's 950 cases is classified as unvaccinated or unknown ^[24], and 95% of the state's cases as of February 6 fell into that category ^[8].

A small share of breakthrough cases is expected, not evidence of vaccine failure: two MMR doses are 97% effective against measles, not 100% ^[23][2].

Most 2026 cases were not isolated importations. As of the February 6, 2026 CDC update, 92% of confirmed cases — 671 of 733 — were outbreak-associated ^[8].

Sustained local transmission, not travel, was driving the 2026 numbers. CDC has warned that a year of continuous spread would put the country's measles elimination status at risk ^[8].

Measles is "one of the most highly communicable infections," according to UChicago Medicine ^[22]. UCLA Health reports it is roughly six times more contagious than COVID-19: one infected person "can infect up to 18 others in an unvaccinated population," compared with a transmission rate of one to three for COVID-19, and an infected person leaves a room contagious for two hours afterward ^[2].

For someone without immunity, exposure is close to decisive — "if you are not vaccinated or immune, there is a 9 in 10 chance you'll get sick if you're exposed" ^[22], and CDC puts the figure the same way: "up to 9 out of 10 susceptible people with close contact to a measles patient will develop measles" ^[14]. Patients are contagious from four days before the rash appears through four days after ^[14].

Measles finds unvaccinated pockets faster than almost any other pathogen in circulation.

CDC states that "national MMR vaccine coverage needs to be at least 95% to prevent outbreaks and maintain elimination status" — a threshold the country no longer meets ^[3]. Kindergarten MMR coverage was 92.5% in the 2024–25 school year, down from 92.7% the previous year and 95.2% in 2019–20, with coverage for MMR, DTaP, polio and varicella declining in more than half of states ^[3]. Vaccination exemptions rose to 3.6% in 2024–25 from 3.3% the year before; Idaho reported the highest exemption rate at 15.4%, and 17 states exceeded 5% ^[3].

County-level data is more granular and no more reassuring: a JAMA study of 2,237 counties found that 78% reported declines in MMR vaccination rates from 2019 through 2024 ^[4].

A national average above 92% conceals the local pockets where measles actually spreads.

During the 2025 measles outbreak — described by CIDRAP as the largest in 30 years — the CDC's social media presence all but disappeared: "From January 1 to August 1, 2025, the CDC posted just 10 times about measles across the three platforms" ^[17]. Researchers identified more than 1,000 measles-related social media posts from 25 major news outlets over the same period, meaning news media rather than public health authorities dominated the conversation ^[17]. By October 2025, more than 1,600 measles cases had been reported across 42 states, the highest annual count since elimination in 2000 ^[17].

The silence came precisely when authoritative public health voices were most needed to counter misinformation.

The early-2026 acceleration was steep. The CDC count stood at 588 cases in the January 30 update ^[20], 733 on February 6 — an increase of 145 ^[8] — and 910 on February 12 ^[1]. That is two consecutive weekly increases of roughly 25%.

For comparison, 2,267 measles cases were reported nationwide in 2025, "the highest annual count in more than three decades" ^[2]; CIDRAP put the 2025 tally at 2,280 ^[1] and CDC's final figure for the year was 2,289 ^[27]. At the mid-February growth rate, the 2026 outbreak was on pace to pass that total within weeks ^[8].

That projection did not hold on that timeline. Growth slowed after mid-February, and the 2026 count did not surpass 2025's 2,289 cases until roughly the midpoint of the year, when CDC reported 2,318 cases and described 2026 as the worst year for measles since 1991 ^[26].

As of the February 6, 2026 update, 23 patients — 3% of cases — had been hospitalized, and no deaths had been reported in 2026 ^[8]. That share is down from 11% in 2025 ^[20]. In South Carolina, at least 18 people, adults and children, had been hospitalized for measles complications as of late January, with no deaths reported in the state ^[7].

A low hospitalization share in one outbreak does not make measles mild. CDC reports that "about 1 in 5 unvaccinated people in the U.S. who get measles is hospitalized," and that "1 to 3 out of every 1,000 children who become infected with measles will die from respiratory and neurologic complications" ^[15][14].

Severity tracks vaccination status, and the 2026 caseload is overwhelmingly unvaccinated [8].

The misinformation narrative claims the MMR vaccine is more dangerous than measles itself. The published data does not support that.

Measles infection risks (per CDC): about 1 in 5 unvaccinated people who get measles in the US is hospitalized ^[15]; 1 to 3 of every 1,000 infected children die from respiratory and neurologic complications ^[14][15]; about 1 child in every 1,000 develops acute encephalitis ^[14][15]. Subacute sclerosing panencephalitis, a rare fatal degenerative brain disease, "generally develops 7 to 10 years after a person has measles, even though the person seems to have fully recovered from the illness" ^[15].

MMR vaccine protection: one dose is 93% effective against measles and two doses are 97% effective, and CDC states plainly that "the MMR vaccine is very safe" with side effects that "are usually mild and go away on their own" ^[23][2].

No credible scientific evidence links MMR to autism, and the evidence base is enormous. A 2014 meta-analysis published in Vaccine pooled data from more than 1.25 million children and found "no link between vaccination and autism or autism spectrum disorder" ^[30]. A 2019 Danish cohort study of more than 650,000 children born between 1999 and 2010 found no increased autism risk in vaccinated versus unvaccinated children, no elevated risk among children with a family history of autism, and no clustering of "regressive autism" after vaccination ^[30]. An earlier Danish registry study of more than 500,000 children born between 1991 and 1998 likewise found "no association between MMR vaccination and the development of autism or ASDs" ^[25].

The largest synthesis is a 2021 Cochrane review — described by Gavi as "the gold standard for such assessments in health care" — covering 138 studies and more than 23 million children, which found MMR and MMRV vaccines highly effective with "no evidence of an increased risk of autism" ^[30]. A separate US cohort of roughly 100,000 younger siblings of children with autism found MMR was "not associated with increased risk of ASD, even among high-risk infants with an older sibling with ASD" ^[25].

The claim at the center of this outbreak's misinformation is not merely unproven — it originated in a paper its own journal retracted as fraudulent, and has been contradicted by studies spanning tens of millions of children [11][13][30].