Blindsiding CDC Experts

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

He has now hijacked the CDC website -- and the CDC itself.

Lena H. Sun at WP:

Vaccine experts at the Centers for Disease Control and Prevention were blindsided by a top deputy to Health Secretary Robert F. Kennedy Jr.’s decision to unilaterally overhaul the childhood immunization schedule, according to current and former agency staff.

U.S. health officials took the unprecedented action Monday to narrow the list of vaccines that the federal government routinely recommends for all children, a shift that leading public health experts and medical organizations warned could weaken protections against preventable deadly diseases.

...

But the overhaul contradicted guidance from career scientists who prepared a presentation outlining how the U.S. vaccine policy is not an international outlier, according to a copy of the presentation obtained by The Washington Post. Five career scientists and researchers, who spoke on the condition of anonymity for fear of retaliation, said they are angered by the bypassing of expertise in Monday’s decision. That process to alter vaccine recommendations, they and several former health officials said, did not include extensive consultation with the agency’s subject matter experts or the CDC’s vaccine advisory panel that is usually done.

...

Deputy Health Secretary and acting CDC director Jim O’Neill, who unlike previous CDC directors, is not a scientist, said he signed a decision memo changing the schedule that was presented by Food and Drug Administration Commissioner Marty Makary, National Institutes of Health Director Jay Bhattacharya and Centers for Medicare and Medicaid Services Administrator Mehmet Oz, according to an HHS press release. President Donald Trump, who ordered the review, and Kennedy, a longtime critic of the childhood vaccine schedule, also praised the change.

A Deadly Move: Changing the Vax Schedule

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

He has now hijacked the CDC website -- and the CDC itself.

Lena H. Sun and Paige Winfield Cunningham at WP:

The Trump administration is overhauling the list of routine shots recommended for all babies and children in the United States, bypassing the government’s typical process for recommending vaccines and delivering on Health Secretary Robert F. Kennedy Jr.’s long-standing goals to upend the nation’s pediatric vaccine schedule.

Effective immediately, the Centers for Disease Control and Prevention will no longer recommend every child be immunized for rotavirus, influenza, meningococcal disease and hepatitis A, according to materials released Monday by the Department of Health and Human Services. Instead, the agency will recommend smaller groups of children and babies should get those vaccines only if they are at high risk or if a doctor recommends it.

...

Under Kennedy’s leadership, federal health agencies have upended and scrutinized childhood vaccination policies. They have launched reviews of the cumulative health effects of the immunization schedule. The CDC eliminated a recommendation for all newborns to receive a hepatitis B vaccine shortly after birth, which researchers and health experts credited with a dramatic plunge in infections. Kennedy directed revisions to a CDC webpage that previously debunked a link between vaccines and autism to instead say health authorities have ignored evidence of a link and studies have not ruled out a purported link.

 Stephanie Soucheray and Liz Szabo at CIDRAP:

Public health experts immediately decried the change. Experts said there’s no reason to change a system that has prevented 1.1 million deaths over the past 30 years.

“Abandoning the U.S. evidence-based process is a dangerous and potentially deadly decision for Americans,” said Jason M. Goldman, MD, president of the American College of Physicians. “The evidence is clear that vaccines prevent deaths, hospitalizations, and spread of disease.”

...

“This is a very dark day for children and for their parents and for our country generally,” said Jesse Goodman, MD, MPH, a professor of medicine and infectious diseases at Georgetown University, who spoke at a press conference of vaccine experts following the announcement.

Goodman compared the announcement to a “torpedo” blowing up vaccination policy. “There will be more diseases, more infection, more hospitalization,” said Goodman, a former Food and Drug Administration (FDA) chief scientist and former director of the agency’s center for biologics evaluation and research.

Private Equity

The Politics of Autism includes an extensive discussion of autism service providers.  Private equity firms now own many of them.   After its purchase by Blackstone, the Center for Autism and Related Disorders went bankrupt.

A release from Brown University:

Private equity firms have acquired more than 500 autism therapy centers across the U.S. over the past decade, with nearly 80% of those acquisitions occurring over a four-year span, according to a new study from researchers at the Brown University Center for Advancing Health Policy through Research.

Study author Yashaswini Singh, a health economist at Brown's School of Public Health, said the work highlights how financial firms are rapidly moving into a sensitive area of health care without much public scrutiny or data on where this is happening or why.

"The big takeaway is that there is yet another segment of health care that has emerged as potentially profitable to private equity investors and it is very distinct from where we have traditionally known investors to go, so the potential for harm can be a lot more serious," Singh said. "We're also dealing with children who are largely insured by Medicaid programs, so if private equity increases the intensity of care, what we're really looking at are impacts to state Medicaid budgets down the road."
Study findings and national context

The findings of the analysis were published in JAMA Pediatrics and offer one of the first national assessments of private equity's growing role in autism therapies and services. Autism diagnoses among U.S. children have risen sharply in recent years, nearly tripling between 2011 and 2022, and the condition has been in the national spotlight amid political debate falsely linking autism to childhood vaccines.

The researchers, Singh said, did not evaluate the impacts of private equity ownership on access to treatment, quality of care or the experience of families seeking services. The findings do suggest that investment has been concentrated in states with higher rates of autism diagnoses among children and states that have fewer limits on insurance coverage.

The researchers identified a total of 574 autism therapy centers owned by private equity firms as of 2024, spanning 42 states. Most of those centers were acquired between 2018 and 2022, the result of 142 separate deals. The largest concentrations of centers were in California (97), Texas (81), Colorado (38), Illinois (36) and Florida (36). Sixteen states had one or no private equity-owned clinics at the end of 2024.

States in the top third for childhood autism prevalence were 24% more likely to have private equity–owned clinics than others, according to the study.

The scale and speed of acquisitions underscore the growing trend of private equity's entry into the market. According to Singh, researchers were prompted to investigate after hearing anecdotal reports from families and health providers about changes following private equity takeovers.

The primary concern is private equity firms putting money over families, said Daniel Arnold, a senior research scientist at the School of Public Health.

"It's all about the financial incentives," Arnold said. "I worry about the same types of revenue generating strategies seen in other private equity-backed settings. I worry about children receiving more than the clinically appropriate amount of services and worsening disparities in terms of which children have access to services."

To establish a baseline of where private equity firms are investing and why, the team used a mix of proprietary databases, public press releases and manual verification of archived websites to track changes in ownership. Unlike public companies, private equity firms and private practices are not required to disclose acquisitions, making data collection challenging and labor-intensive.

The team now hopes to examine how private equity ownership affects outcomes, including changes in therapy intensity, medication use, diagnosis age or how long children stay in treatment. They will determine whether these investments are helping meet real needs or are primarily a way to make money.

"Private investors making a little bit of money while expanding access is not a bad thing, per se," Singh said. "But we need to understand how much of a bad thing this is and how much of a good thing this is. This is a first step in that direction."

US Exports Misinformation to Canada

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

Olivia Bowden at The Guardian:

Canadian officials and public health experts are warning that US health and science institutions can no longer be depended upon for accurate information, particularly when it comes to vaccinations, amid fears that misinformation from the Trump administration could further erode Canadians’ confidence in healthcare.

“I can’t imagine a world in which this misinformation doesn’t creep into Canadians’ consciousness and leads to doubt,” said Dawn Bowdish, an immunologist and professor at McMaster University in Ontario.

Those fears have emerged as the US health secretary, Robert F Kennedy Jr, has forwarded an anti-vaccine agenda. In December, a panel appointed by Kennedy voted to remove a longstanding recommendation by the US Centers for Disease Control and Prevention (CDC) that all newborns be vaccinated against hepatitis B.

The CDC also updated its website in November at the instruction of Kennedy to claim that “studies have not ruled out the possibility that infant vaccines cause autism”, which top public health experts have decried as false.

The agency’s move toward misinformation and away from public health leadership makes it more difficult to combat distrust in vaccinations in Canada, says Bowdish.

...

A December poll on vaccination hesitancy by research firm Leger Healthcare found that while most Canadians (74%) have confidence in vaccines, hesitancy has increased primarily due to fears around safety driven by social media and government mistrust.

The survey also found that 17% of those who expressed a lack of confidence in vaccines say they get their information from US government websites.

 

On-Time MMR Vaccination is Down

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio. 

Liz Szabo at CIDRAP:

In another sign of growing vaccine hesitancy, a new report finds that the percentage of US toddlers vaccinated on time against measles, mumps and rubella (MMR) has fallen since the pandemic.

The percentage of 2-year-olds given the MMR vaccine fell from 80% in 2021 to 77% in 2024, according to a study published today in JAMA Network Open. The new study included nearly 322,000 children with regular access to care.

The researchers found that the strongest predictor of missing the MMR shot by age 2 was late administration of the vaccines recommended for babies at 2 months and 4 months of age.

The American Academy of Pediatrics recommends giving children a first dose of MMR vaccine at 12 to 15 months of age and a second dose at 4 to 6 years. Research shows that at least 95% of children need to receive both doses on time to keep measles from spreading.

Reduced vaccination levels have helped fuel ongoing measles outbreaks across the United States that affected more than 2,000 people in 2025. Two Texas children died after contracting measles last year.

William Vaillancourt at The Daily Beast:

Measles may have spread at a Noah’s Ark-themed creationist museum in Kentucky earlier this week, the state’s health authority said.

Visitors and staff at Ark Encounter in Williamstown are being encouraged to be on the alert for symptoms of the highly contagious—and vaccine-preventable—disease through Jan. 19, the Kentucky Department of Public Health explained, following a potential exposure on Monday.

“An unvaccinated, out-of-state traveler stayed at the Holiday Inn & Suites in Dry Ridge from Dec. 28 to 30, 2025 and visited the Ark Encounter on Dec. 29, 2025,” the agency said in a Facebook post. It then noted that “vaccination is the best protection against measles,” and that young, unvaccinated children are particularly at risk of developing complications.

...

Ark Encounter, which includes exhibits showing dinosaurs and humans living together, allows children 10 years old and under to enter for free. It reported 1 million visitors from mid-2017 to mid-2018, its second year of operation.

Iowa Lifts Dollar Cap and Age Limit for Insurance

The Politics of Autism includes an extensive discussion of insurance and Medicaid services for adults with intellectual and developmental disabilities.

Kayla James at KCCI-TV in Des Moines:

A new Iowa law that expands insurance coverage for Iowans with autism, impacting families across the state went into effect Jan. 1. It’s one many are calling "life-changing," including a family in Ankeny.

The Lust family says the law, HF 330, has the power to make real change for so many people across the state. It updates state insurance rules to remove annual and lifetime dollar caps on autism coverage in group plans covered under Iowa law, meaning insurers can no longer cut off autism benefits once a family reaches a specific spending limit. It also removes an age cap.

Under the previous state law. coverage was capped at $36,000 per year, and Iowans with autism spectrum disorder were covered until they turned 21-years-old.

...

The law also adds limits on insurance companies. It prevents them from capping the number of outpatient visits for autism treatment or applied behavior analysis.

State Representative Eddie Andrews sponsored the bill.  He is a candidate for the Republican gubernatorial nomination.

Andrews says institutions have been hard at work since the bill was signed to make sure they can provide care for adults, too.

“Normally it would have already started on July 1 of last year, but we gave them extra time to expand and prepare for today, so they should be ready to go,” said Andrews.

These changes give a sense of security for people and families like Brandon’s, who continue to watch him succeed and grow.

“A lot of us parents — we call it 'the cliff' when they turn 18 because a lot of things start ending — and so it’s nice that this is one thing that’s going to be able to continue for him,” said Kerry Lust.

Vaccination Rates

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

As of December 30, CDC reported a total of 2,065 confirmed measles cases this year -- the most since 1992.

Lauren Weber, Caitlin Gilbert, Dylan Moriarty and Joshua Lott at WP:

The share of U.S. counties where 95 percent or more of kindergartners were vaccinated against measles — the number doctors say is needed to achieve overall protection for the class, known as “herd immunity” — has dropped from 50 percent before the pandemic to 28 percent, according to The Post’s examination of the public records from 44 states and the District of Columbia.

Most of the counties that previously lacked herd immunity for kindergarten classrooms got worse, according to the Post analysis, which in most cases compared the academic years 2018-2019 and 2024-2025.

...

The Post’s findings show that at least 5.2 million kindergarten-age children in the U.S. are living in counties where vaccination rates for classrooms have fallen below the herd immunity threshold — up from about 3.5 million before the pandemic. While the vast majority of those who receive the measles vaccine are protected from severe illness and death, without herd immunity measles can still spread among those not immune, including those who cannot be vaccinated because of age or because they are immunocompromised.

Out of the 44 states reporting county-level rates, 36 and the District of Columbia also reported them for individual schools or districts. At least 19,000 schools — nearly half of schools in the Post analysis — were more vulnerable to outbreaks.

...
Medical specialists and public health experts expect more children will be left unprotected given policies advanced by Health Secretary Robert F. Kennedy Jr., an anti-vaccine activist 
who is rolling back government vaccine policies and recommendations

 ...

The national anti-vaccine organization that Kennedy founded, Children’s Health Defense, has linked vaccines to autism, an assertion not supported by evidence and which scientists say is false.

Mister Measles

 In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

He has now hijacked the CDC website -- and the CDC itself.

As of December 30, CDC reported a total of 2,065 confirmed measles cases this year -- the most since 1992.

Aria Bendix at NBC:

A sizable uptick in measles cases in the ongoing outbreak in South Carolina has put the U.S. on the precipice of losing its elimination status.

South Carolina’s health department on Tuesday reported 20 new measles cases since Friday, bringing the state’s total this year to 179. That tally is higher than the number of measles cases recorded for the entire U.S. in six of the last 10 years.

This year, the country has counted over 2,000 measles cases, 93% of which were among unvaccinated people or those with an unknown vaccination status, according to the Centers for Disease Control and Prevention. That's by far the most since the disease was first considered eliminated in the U.S. 25 years ago.

Measles is considered eliminated in a country once it no longer spreads constantly for a full year. In the U.S., that deadline is fast approaching: Transmission of the highly contagious disease has been sustained since around Jan. 20. Unless that trend comes to an abrupt halt in the next three weeks — which is highly unlikely — the country could lose its elimination status, as Canada did in November.

About the Coalition of Autism Scientists

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.

A number of posts discussed Trump's support for the discredited notion.

 Another leading anti-vaxxer is presidential candidate Robert F. Kennedy, Jr.  He has repeatedly compared vaccine mandates to the Holocaust.  Rolling Stone and Salon retracted an RFK article linking vaccines to autism.  He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

He is now Trump's secretary of HHS. 

Tager-Flusberg, H. (2025), Debate: Standing up for science – how to combat misinformation in child mental health: protecting the integrity of autism research and practice in the United States. Child Adolesc Ment Health. https://doi.org/10.1111/camh.70058.  Abstract:

In 2025, the Coalition of Autism Scientists was formed to counter the misinformation and pseudoscience that was being advanced at the highest levels of the federal government in the United States. The background and history of how the Coalition was formed and its major activities, which include regular meetings, issuing public statements, and providing information and interviews to the media, are described. The importance of engaging in active advocacy in support of autism science is discussed along with some examples of the Coalition's impact. Given the direction that politics is going, sowing greater dissent between science and the public, continued vigilance in support of the highest quality research is critical if we are to meet the urgent needs of autistic people and their families.

Denmark's Vaccine Schedule

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

Polls show that many Americans either believe the myth or think it could be true.

Trump has spread this myth and withdrawn the US from the World Health Organization.

Now his administration is actively defending disinformation.  Trump has said that getting "too many shots" causes autism.  He's wrong, as Matthew Herper writes at STAT:

Researchers have had two responses to this allegation: First, data don’t indicate that vaccines increase the risk that children will contract other infections. Second, vaccines have become much more targeted over time, often involving fewer antigens to stimulate the immune system than earlier versions. Vaccines for pneumococcus, whooping cough, and other diseases now often contain only sugar molecules or proteins from the coat of a virus in order to produce an immune response. By this measure, children get more shots, but they contain fewer antigens.

Amelia Nierenberg and Maya Tekeli at NYT:

The United States, a nation of 343 million people with a complex and overburdened health care system, is poised to adopt the childhood vaccine recommendations used in Denmark, a country of six million with universal health care. The decision has alarmed public health experts in both countries.

Robert F. Kennedy Jr., the U.S. health secretary, is expected to announce the move in the new year. It would reduce the number of immunizations required for American children to 10 from 17, radically changing the recommended vaccines without the deliberative process that the United States has relied on for decades.

Instead, Mr. Kennedy is following a presidential directive issued on Dec. 5 by President Trump, which said the United States was an “outlier” in the number of vaccines children receive, pointing to Denmark, Germany and Japan as peer countries that recommend fewer.

...
 Kristian G. Andersen, a Danish-American professor in the immunology and microbiology department at the Scripps Research Institute in California, said the United States already has one of the best standards for vaccine recommendations.

“Their childhood vaccine program covers almost everything it should,” Dr. Andersen said.

“The Danish program does not,” he added, noting that the Nordic country “has one of the most minimal vaccine programs among wealthy nations.”

“Denmark is the outlier,” Dr. Andersen said. “Not the United States.”

...

Denmark has universal health care; that means Danes can get treated more easily for diseases and often seek medical help earlier. Its people do not pay for most doctors’ appointment.

In the United States, about 8 percent of the population is uninsured. Even with health insurance, some American families need to decide whether a child is sick enough to justify the potential cost of a doctor’s visit.

Bobby's War on Science Will Have Casualties

In The Politics of Autism, I analyze the myth that vaccines cause autism. This bogus idea can hurt people by allowing diseases to spread.    Examples include measles, COVID, flu, and polio.  A top antivaxxer is HHS Secretary RFK Jr. He is part of the "Disinformation Dozen." He helped cause a deadly 2019 measles outbreak in Samoa.

Polls show that many Americans either believe the myth or think it could be true.

Trump has spread this myth and withdrawn the US from the World Health Organization.

Now his administration is actively defending disinformation.

Dr. Benjamin Mazer at NYT writes about RFK Jr's war on science.

Take the false idea that vaccines cause autism. The Centers for Disease Control and Prevention once plainly declared that they didn’t. Mr. Kennedy instructed the agency to take a different position: “The rise in autism prevalence since the 1980s correlates with the rise in the number of vaccines given to infants,” the C.D.C.’s website has been updated to read.

This sort of claim is typical of the anti-vaccine community. A nearly identical statement appears on the website of Children’s Health Defense, the anti-vaccine group Mr. Kennedy was formerly a part of. It isn’t true: Studies have shown that neither the number of active ingredients nor the amount of additives in vaccines corresponds to an increased rate of autism. But it sounds faintly data-driven and taps into a widely held belief that society has become overmedicalized.

Vaccine critics have won converts by branding their opposition to proven public health interventions as advocacy for individual liberty. “The decision to vaccinate is a personal one,” Mr. Kennedy wrote last March in response to the country’s measles outbreak. The C.D.C.’s acting director, Jim O’Neill, has followed the health secretary’s lead. In December he refused to endorse universal vaccination as a solution to the measles outbreaks, only going so far as to issue a vague recommendation for parents to “consult with their health care providers about vaccination options.”

Most parents, for the time being, seem to trust their doctor’s advice. Childhood immunization rates remain relatively high in the United States. But it has taken only a slight decline in vaccine confidence to set off the disease outbreaks we are seeing. It is easier for anti-vaccine groups to chip away at public trust than it is for the medical community to rebuild it.

At The Atlantic, Katherine J. Weu writes of the tendency to shrug off outbreaks of measles.

Measles was never inconsequential, though. Even a case that is initially “mild” can wipe out defenses that people have built up to other diseases—a kind of “immune amnesia” that can leave them more vulnerable to infection for months or years. Painful ear infections and prolonged bouts of diarrhea can accompany close to a tenth of measles cases. Some 5 percent of infections result in pneumonia that can eventually turn fatal; rarely, measles can also leave children deaf or blind. The disease also tends to hit undernourished, immunocompromised, and pregnant people particularly hard, and many of the severest cases tend to occur in the youngest children. This year, the U.S. has clocked more than 1,900 measles infections—the most the country has documented since 1992—and 11 percent have resulted in hospitalizations. Three people have died, two of them children.

In the prescient 2011 movie Contagion, major airports -- Hong Kong (HKG), Chicago O'Hare (ORD), and Minneapolis-St. Paul (MSP) -- serve as key points for Patient Zero (Gwneth Paltrow) to spead a deadly fictional virus around the world.

Special Ed Teacher Shortages Will Get Worse

In The Politics of Autism, I write about social services, special education, and the Individuals with Disabilities Education Act (IDEA). 

Anna Merod at K-12 Dive:

According to a July analysis by the Learning Policy Institute, 45 states reported teacher shortages in special education during the 2024-25 school year.

In September, the U.S. Commission on Civil Rights released the findings of its yearlong investigation into the national special educator shortage. The federal civil rights panel found that the widespread shortage is leading to a lack of supports and services that are needed to help the growing population of students with disabilities thrive in schools.

The findings were released just a couple of months before the 50th anniversary of the landmark federal law, the Individuals with Disabilities Education Act. The historic legislation, signed into law on Nov. 29, 1975, guaranteed that students with disabilities have the right to a free and appropriate public education nationwide.

Reflecting on IDEA’s big anniversary, educators and researchers said they’re still hopeful about several evolving and innovative approaches to recruiting and retaining more special education teachers. Those solutions include: 

• Paying special educators more than general education teachers.
• Offering targeted training and professional development for paraprofessionals, school administrators and prospective special educators.
• Developing special education teacher pipelines through grow-your-own programs.

At the same time, teacher preparation experts have expressed concerns about the Trump administration’s goal to downsize and eventually eliminate the U.S. Department of Education — especially when it comes to ongoing special educator shortages.

President Donald Trump, for instance, proposed in his fiscal year 2026 budget that IDEA Part D personnel development grants be zeroed out and that newly allocated funds go to IDEA Part B programs through a single state block grant program.

Trump’s attempt to drastically reduce the number of staff in the Education Department’s Office of Special Education Programs during the recent federal government shutdown also raised red flags among advocates. Their chief concern: that it would become very difficult to administer and oversee federal grants like IDEA Part D that help address special educator shortages.

The state block grant consolidation proposal, though unpopular among Congressional lawmakers, would particularly harm the ability of teacher prep programs to train high-quality special education teachers, said advocates and experts.

Autisms

 In The Politics of Autism, I discuss various ideas about what constitutes and causes autism. 

Ariana Eunjung Cha at WP:

Natalie Sauerwald is one of the lead authors of the subtypes study and a computational biologist at the Flatiron Institute, part of the Simons Foundation, which funds scientific research. She compared earlier autism research to assembling a jigsaw puzzle, only to find that the pieces didn’t quite fit — not because the image was unclear but because “the box had always contained several puzzles, shuffled together.”

There isn’t just one autism, Sauerwald said: “There are many autisms.”

... 

The work published in July in Nature Genetics detailed the four categories.

• Broadly affected: The smallest group — about 10 percent of participants — faced the steepest challenges, marked by developmental delays, difficulties with communication and social interaction, and repetitive behaviors that touched nearly every part of life.
• Mixed autism with developmental delay: Roughly 19 percent showed early developmental delays but few signs of anxiety, depression or disruptive behavior. Researchers call this group “mixed” because its members vary widely in how strongly they display social or repetitive behaviors.
• Moderate challenges: About a third of participants fell into this group, showing the hallmark traits of autism — social and communication differences and repetitive habits — but in subtler ways and without developmental delays.
• Social and/or behavioral: The largest group, around 37 percent, met early developmental milestones on time yet often grappled with other conditions later on, including ADHD, anxiety, depression or obsessive-compulsive disorder.

...

That breakthrough idea was given another boost in October when a second study — published in Nature by an entirely different team using separate data — arrived at essentially the same conclusion: Genetically distinct forms of autism may unfold on different life timelines. The new analysis, based on data from the United States, Europe and Australia, suggested that children diagnosed after age 6 carried distinct genetic profiles and that their form of autism looked strikingly different from the early-childhood type — less like a developmental delay and more akin to conditions such as depression, ADHD or post-traumatic stress disorder.