(NEW YORK) — Longer periods of extreme heat has been found to accelerate biological age in older adults by up to two years, according to new research.
More heat days over time correlated with deterioration at the molecular and cellular level in adults 56 years or older, likely because the biological deterioration accumulates over time and eventually leads to disease and disability, Eunyoung Choi, a postdoctoral associate at the University of California’s Leonard Davis School of Gerontology, told ABC News.
Researchers at the University of Southern California studied blood samples from 3,686 adults starting at an average chronological age of 68 years with varying socioeconomic backgrounds across the U.S. and compared epigenetic aging trends to the number of extreme heat days in the participants’ places of residence, according to a study published Wednesday in Science Advances.
“Epigenetic age is one way we measure biological aging, which tells us how well our body is functioning at the physical, molecular and the cellular levels,” Choi said. “…We know that some people seem to age faster than others, and that’s because biological aging doesn’t always match chronological age.”
Regression modeling showed that more heat days, or longer-term heat, over one and six years increased biological age by 2.48 years. Short and mid-term heat also increased biological age by 1.07 years, according to the paper.
Extreme heat was defined as the daily maximum heat index — derived from both temperature and humidity — with a “caution” range of between 80 degrees to 90 degrees Fahrenheit and an “extreme caution” range of between 90 degrees and 103 degrees Fahrenheit, in accordance with the National Weather Service, according to the paper. “Extreme danger” was defined as any heat index level over 124 degrees Fahrenheit.
The researchers compared the epigenetic age of participants from regions with long periods of extreme heat to those living in cooler climates. There was a 14-month difference in epigenetic age between residents living in places like Phoenix, Arizona, than milder places like Seattle, even after accounting other individual and community-level differences, like income, education, physical activity and smoking, Choi said.
“Two people that had identical sociodemographic characteristics and similar lifestyles, just because one is living in a hotter environment, they experience additional biological aging,” she said.
The 14-month differences is comparable to effects seen with smoking and heavy alcohol consumption — two well-established risk factors of accelerated biological aging, the researchers found.
DNA methylation — the process of chemical modification to DNA that tends to change as people age — is “highly responsive” to environmental exposures like social stress, pollution and, in this case, extreme heat, Choi said.
Previous research has linked extreme heat to serious health risks like cardiovascular disease, kidney dysfunction, hospitalization and even death, Choi said. But prior to this research, scientists did not fully understand what is occurring at the biological level before those health issues appear, Choi added.
“The physical toll of the heat might not show up right away as a diagnosable health condition, but it could be taking a silent toll at the cellular and the molecular level,” Choi said.
It’s important to uncover potential hidden effects of heat on the body because it can serve as an “important precursor” before they turn into more serious health conditions, Choi said.
“We can intervene at the earlier stage,” she added.
Humidity also plays a big role in how the body responds to heat, especially for older adults, Choi said.
“As we age, our bodies don’t cool down as rapidly,” she said.
The new research provides a foundation for the development of targeted public health interventions, the researchers said.
“This provides strong evidence critical for guiding public policy and advocacy initiatives aimed at developing mitigation strategies against climate change,” Choi said.
ABC News Medical Unit’s Dr. Jessica Yang contributed to this report.
(LUBBOCK, Texas) — An unvaccinated school-aged child in Texas has died of measles, the first associated with an outbreak in the western part of the state that has infected more than 100 people.
Lubbock city spokesperson Lauren Adams confirmed the death to ABC News on Wednesday.
In a press release, the Texas Department of State Health Services (DSHS) said the child was hospitalized in the northwestern city of Lubbock last week and tested positive for measles.
As of Wednesday, 124 cases of measles have been confirmed associated with the outbreak, according to data from DSHS.
Almost all of the cases are in unvaccinated individuals or individuals whose vaccination status is unknown, and 18 people have been hospitalized so far, DSHS said.
Children and teenagers between ages 5 and 17 make up the majority of cases with 62, followed by 39 cases among children ages 4 and under.
The outbreak began in Gaines County, which has become the epicenter, with 80 cases confirmed among residents, according to DSHS.
The outbreak has since spread to several counties in the region and is “suspected” to have spread into New Mexico, according to New Mexico Department of Health (NMDOH). Nine cases have been confirmed in Lea County, which borders Texas. Of the nine cases, four are among children, according to NMDOH.
“This death underscores the real danger of measles — it’s a severe disease that can take lives despite being preventable with vaccination,” said Dr. John Brownstein, an epidemiologist and ABC News contributor. “Every new case is a reminder of why vaccination is critical. Tragically, with an outbreak of this scale, a fatal case was not unexpected, especially among those unvaccinated. Given how contagious measles is, we anticipate more cases in the coming weeks.”
During Tuesday’s Cabinet meeting, Health and & Human Services Secretary Robert F. Kennedy Jr. responded to a question about the outbreak, saying the agency was following the cases in Texas.
Kennedy appeared to downplay the outbreak, noting there have been four outbreaks so far this year compared to 16 last year. However, the number of cases in Texas alone amount to nearly half of the 285 cases confirmed in 2024.
“It’s not unusual; we have measles outbreaks every year,” he said.
Measles is one of the most contagious diseases known to humans. Just one infected patient can spread measles up to nine out of 10 susceptible close contacts, according to the Centers for Disease Control and Prevention (CDC).
Health officials have been urging anyone who isn’t vaccinated to receive the measles, mumps, rubella (MMR) vaccine.
The CDC currently recommends people receive two vaccine doses, the first at ages 12 to 15 months and the second between 4 and 6 years old. One dose is 93% effective, and two doses are 97% effective. Most vaccinated adults don’t need a booster.
Measles was declared eliminated from the U.S. in 2000, due to the highly effective vaccination program, according to the CDC. However, vaccination rates have been lagging in recent years.
About 93% of kindergarteners nationwide received select routine childhood vaccines, including the MMR vaccine, for the 2022-23 school year, according to a November 2023 CDC report.
This is about the same as the previous school year, but lower than the 94% seen in the 2020-22021 school year and the 95% seen in the 2019-2020 school year, prior to the COVID-19 pandemic. The latter percentage had been the standard for about 10 years.
ABC News’ Youri Benadjaoud contributed to this report.
(LUBBOCK, Texas) — An unvaccinated school-aged child in Texas has died of measles, the first associated with an outbreak in the western part of the state that has infected more than 100 people.
Lubbock city spokesperson Lauren Adams confirmed the death to ABC News on Wednesday.
In a press release, the Texas Department of State Health Services (DSHS) said the child was hospitalized in Lubbock, located in northwestern Texas, last week and tested positive for measles.
As of Wednesday, 124 cases of measles have been confirmed, according to data from DSHS.
Almost all of the cases are in unvaccinated individuals or individuals whose vaccination status is unknown, and 18 people have been hospitalized so far, DSHS said.
Children and teenagers between ages 5 and 17 make up the majority of cases with 62, followed by 39 cases among children ages 4 and under.
This is a developing story. Please check back for updates.
A general view of the World Health Organization (WHO) on April 28, 2009, in Geneva, Switzerland. (Harold Cunningham/Getty Images)
(DEMOCRATIC REPUBLIC OF CONGO) — The World Health Organization has reported that there is a deadly “unknown disease” spreading in one region within the Democratic Republic of Congo.
Local health officials in Congo are partnering with the World Health Organization to investigate.
The phrase “unknown disease” primarily means that the disease has not yet been identified.
In previous cases, the cases are linked to a known disease, but a lack of available testing leads to lack of certainty.
For example, there was a separate report of an “unknown disease” in December of last year in Congo that was later attributed to illnesses from malaria and respiratory illnesses.
The latest numbers from the WHO’s Africa Region show that there are 431 cases linked to the outbreak and 53 deaths since January.
Early investigations traced the outbreak’s origin to three kids, all under 5 years old, who developed symptoms after eating a bat carcass.
Symptoms included fever, headache, diarrhea and fatigue – which later progressed to signs associated with hemorrhagic fevers and death.
Ebola and Marburg have already been ruled out, officials say. Nearly half of deaths occurred within 48 hours after symptoms start.
“The remote location and weak healthcare infrastructure increase the risk of further spread,” the WHO notes in its report.
(WASHINGTON) — The Centers for Disease Control and Prevention (CDC) said on Monday that the new coronavirus found in bats is currently not a cause for concern.
There is no reason to believe the virus poses a threat to public health at the moment and no infections have been detected in humans, according to the federal health agency.
“CDC is aware of a publication about a new bat coronavirus, but there is no reason to believe it currently poses a concern to public health,” the agency said in a statement. “The publication referenced demonstrates that the bat virus can use a human protein to enter cells in the laboratory, but they have not detected infections in humans.”
Chinese researchers, including from the Wuhan Institute of Virology and Guangzhou Medical University, published a paper in the journal Cell on Friday indicating they had discovered a new bat coronavirus that could have the potential to infect humans.
The newer coronavirus is known as HKU5-CoV-2 and is a type of merbecovirus, which is the same family of another coronavirus known to infect humans called Middle East Respiratory Syndrome (MERS).
In a lab study, the new coronavirus was found to have the potential to enter cells through the ACE2 receptor, a protein found on the cells’ surface.
This is the same way the virus that causes COVID-19 infects people, which theoretically means the new coronavirus could pose a risk to spilling over into humans.
The spike protein of the new coronavirus infected human cells that had high levels of the ACE2 receptor in test tubes, as well as in small models of human airways and intestines.
The researchers found that the virus did not enter human cells as readily as the virus that causes COVID-19 — which is called SARS-CoV-2 — writing that the “risk of emergence in human populations should not be exaggerated.”
None of the animal studies that were conducted examined the virus’s ability to cause disease or its transmissibility.
If the virus were to infect humans, the researchers suggested antiviral drugs and monoclonal antibodies — laboratory-produced proteins that mimic the antibodies the body naturally creates when fighting a virus — could be effective.
There are hundreds of coronaviruses circulating in nature. Only a few can infect humans, causing illnesses ranging from mild respiratory tract infections to more severe conditions such as bronchitis or pneumonia.
Coronaviruses include some variations of the common cold, the virus that causes MERS, severe acute respiratory syndrome (SARS) and the virus that causes COVID-19.
The researchers wrote that “bats harbor the highest proportion of genetically diverse coronaviruses,” posing a risk of spilling over into humans.
(NEW YORK) — Flu activity remains “elevated” in the United States but is starting to show signs of abating, according to new federal data published Friday.
The 2024-25 flu season was classified by the Centers for Disease Control and Prevention (CDC) as a “high” severity season overall and for all age groups, making it the first high severity season since 2017-2018.
During the week ending Feb. 15, 6.8% of visits to doctors’ offices were for flu-like illness, down from 7.7% of visits over the previous two weeks, CDC data shows.
Emergency department visits for flu also fell to 6.4% during the week ending Feb. 15 from more than 8% for the two weeks prior.
Additionally, 26.9% of tests came back positive for flu during the week ending Feb. 15. This is higher than the peak of 18.2% last flu season but lower than the 31.4% recorded over the previous two weeks.
The CDC estimates there have been at least 33 million illnesses, 430,000 hospitalizations and 19,000 deaths from flu so far this season
At least 86 pediatric flu deaths have been recorded so far, with 18 reported the week ending Feb. 15.
It comes as overall respiratory illness activity is listed as “high” nationwide, CDC data shows.
As of Friday, nine states are listed as having “very high” levels of respiratory virus activity and 14 states are listed as “high.” The remaining states are listed as having “moderate” or “low” levels.
Comparatively, 12 states were listed as “very high” and 20 states were listed as “high” last week.
Meanwhile, although COVID-19 activity is “elevated” in many areas of the U.S., CDC data shows emergency department visits are at low levels and the number of laboratory tests coming back positive is stable.
Respiratory syncytial virus activity was also described as “elevated” but declining in most areas of the U.S., according to the CDC.
Public health experts have recommended children and adults receive the flu and COVID vaccine as well as older adults receive the RSV vaccine, but coverage is “low,” according to the CDC.
As of Feb 8, only 45.3% of adults were vaccinated against the flu and 23,1% were vaccinated with the updated 2024-25 COVID-19 vaccine. Additionally, just 46.7% of adults ages 75 and older have received the RSV vaccine, according to CDC data.
Nearly half of all children are vaccinated against the flu at 45.8%, but just 12.1% have received the updated COVID-19 vaccine.
(AUSTIN, Texas) — The number of measles cases linked to an outbreak in western Texas has grown to 90, according to new data released on Friday.
Almost all of the cases are in unvaccinated individuals or individuals whose vaccination status is unknown, and 16 people have been hospitalized so far, according to the Texas Department of State Health Services. Five cases included those who have been vaccinated.
A DSHS spokesperson previously told ABC News that this marks the largest measles outbreak in the state in more than 30 years.
Children and teenagers between ages 5 and 17 make up the majority of cases with 51, followed by 26 cases among children ages 4 and under.
Gaines County is the epicenter of the outbreak, with 57 cases confirmed among residents, according to DSHS. State health data shows the number of vaccine exemptions in the county have grown dramatically.
Roughly 7.5% of kindergarteners had parents or guardians who filed for an exemption for at least one vaccine in 2013. Ten years later, that number rose to more than 17.5% — one of the highest in all of Texas, according to state health data.
Meanwhile, in neighboring New Mexico, at least nine cases have been confirmed in Lea County, which borders Texas, a spokesperson for the state Department of Health told ABC News on Friday.
Similarly to the local outbreaks, all of the nationally confirmed cases are in people who are unvaccinated or whose vaccination status is unknown.
Measles is one of the most contagious diseases known to humans. Just one infected patient can spread measles up to nine out of 10 susceptible close contacts, according to the CDC.
Health officials have been urging anyone who isn’t vaccinated to receive the measles, mumps, rubella (MMR) shot.
The CDC currently recommends people receive two vaccine doses, the first at ages 12 to 15 months and the second between 4 and 6 years old. One dose is 93% effective, and two doses are 97% effective.
(NEW YORK) — A personalized mRNA vaccine may reduce the risks of pancreatic cancer returning after surgery, according to a preliminary study published Wednesday in the journal Nature.
Pancreatic cancer is one of the most aggressive cancers, with a typical survival rate of only about a year after the diagnosis according to the study.
While the findings are encouraging, the vaccine is still in early testing and will likely take years before it becomes widely available — assuming ongoing trials continue to show success, according to Dr. Vinod P. Balachandran, lead investigator of the trial and senior author of the study.
In this small, preliminary trial of 16 patients, half had a strong immune response to the vaccine. Most of these responders remained cancer-free for more than three years, much longer than those who didn’t respond.
The vaccine works by training specialized immune system cells, known as T cells, to recognize and attack the cancer.
Researchers couldn’t track tumor shrinkage because all patients had surgery to remove visible cancer before vaccination. However, they found that the vaccine produced long-lasting T cells that may keep fighting cancer for years.
“This is one way through which you can make lots of T cells, and you can make these T cells such that they can persist for a long time in patients and retain their function,” Balachandran said.
Balachandran said “to be able to get an immune response has been very challenging,” especially when an illness like pancreatic cancer typically does not respond to vaccines, which highlights the significance of these findings.
A larger trial is now underway to confirm the results. If successful, this approach could lead to new ways to treat or even prevent pancreatic and other advanced cancers.
Overall, Balachandran said this study can “provide some important clues on how you would be able to develop vaccines more broadly for other cancers.”
“Hopefully this information that we will learn from these clinical trials will give us information to know apply vaccines in other settings, such as primary prevention, meaning preventing cancers from occurring even before they occur, with vaccines or perhaps also using it to treat patients who have more advanced disease,” Balachandran said.
(WASHINGTON) — New research shows the far-reaching effects of the abortion bans that have proliferated the United States since the Supreme Court struck down Roe v. Wade in 2022.
Three new studies have provided some of the first nationwide data on the effects of those bans in the states where they are currently active — revealing more births but also a rise in infant deaths.
The impact of those bans have even spread to states where abortion is still legal, the studies showed.
In the first study, Johns Hopkins researchers found that birth rates rose 1.7% in states with abortion bans. It showed that the bans primarily affect racial minorities, younger individuals and those with lower income or education, especially in the South.
“Those experiencing the greatest structural disadvantages and in the states amongst the worst in maternal and child health outcomes experience the greatest impact of these abortion bans on the number of live births,” Suzanne Bell, PhD, MPH, the paper’s lead author and an assistant professor at Johns Hopkins Bloomberg School of Public Health, told ABC News.
“Many of these occurred in states with among the weakest social services and worst outcomes, potentially deepening existing disparities and placing additional burdens on already strained resources,” she said.
At the same time, infant deaths rose in states with abortion bans, according to another Johns Hopkins study. Analyzing birth and death records from 2012 to 2023, Bell’s team noted 478 more infant deaths than expected in 14 states with the bans. The highest increases were seen in Black infants (about an 11% higher death rate), infants in Southern states and infants born with severe medical conditions.
“When you look at Texas’ contribution to the overall findings, we see that Texas is responsible for 73% of the additional births and 80% of the excess infant deaths,” Bell said.
But states without bans have also felt the effects.
Abortion also rose in Colorado, a state that maintained access to abortion with no gestational limits, according to a research letter recently published in JAMA Network Open.
Colorado State University researchers found that abortions for out-of-state residents in Colorado rose from 13% in 2020 to 30% in 2023. Abortions among Colorado residents also peaked six months after Texas’ abortion ban, with an 11% increase in first-trimester abortions and an 83% increase in second-trimester abortions compared to before the ban.
The surge in demand led to delays, possibly raising costs, emotional toll and procedure complexity, the authors said. However, second-trimester abortions have since stabilized, possibly due to expanded telehealth, self-managed abortions and access in other states, they added.
Currently, abortion is illegal in 12 states, according to the Kaiser Family Foundation, and 29 states have some sort of abortion limitation based on gestational age. Nine states have no restriction on abortion.
“The literature we have demonstrates that not being able to obtain an abortion has negative physical, mental and economic implications for birthing persons, their children and their families — and undermines achieving health equity,” Bell said. “These bans are deepening or worsening some of these existing population health disparities that exist.”
Jessica Yang, DO, is a family medicine resident at Main Line Health Bryn Mawr Hospital and a member of the ABC News Medical Unit.
(WASHINGTON) — During his confirmation hearings two weeks ago to lead the Department of Health & Human Services (HHS), Robert F. Kennedy Jr. repeated several unfounded claims about autism.
Kennedy, an environmental lawyer who has made money through books, speeches and lawsuits while sharing vaccine skepticism, refused to say that vaccines don’t cause autism despite many high-quality studies finding no such link.
He stated during the hearing that autism rates have “have gone from 1 in 10,000 … and today in our children, it’s one in 34.” His claims have been repeated by President Donald Trump on Truth Social.
It’s unclear where Kennedy got his 1 in 10,000 statistic. In 2000, approximately 1 in 150 children in the U.S. born in 1992 were diagnosed with autism compared with 2020, during which one in 36 children born in 2012 were diagnosed, according to data from the Centers for Disease Control and Prevention.
Some psychiatrists and autism experts told ABC News it’s important to highlight the rising rates of autism, and that at least Kennedy is putting a spotlight on it.
“On the bright side, I think it is really important to place an emphasis on these very high rates, it’s kind of great putting a spotlight on autism, these increased rates,” Dr. Karen Pierce, a professor in the department of neurosciences at the University of California, San Diego and co-director of the UCSD Autism Center of Excellence, told ABC News. “We need more funding. We need more infrastructure to support everybody who is now recognized as on the spectrum. So, I think that that’s actually a really good thing.”
However, the experts said Kennedy and others are missing important context about why autism rates are increasing. They say reasons may include a combination of widening of the definition of the spectrum and of types of symptoms associated with autism spectrum disorder (ASD) as well as people having children at older ages, better awareness and access to diagnostic testing.
“With the rates increasing, there certainly are valid reasons for that,” Pierce said. “There’s better awareness, and doctors can find autism a lot easier than they could before in the past…. and I think a very big reason is just better record keeping nowadays and easier access to reviewing records.”
What is autism?
ASD is a developmental disability caused by differences in the brain, according to the CDC.
People with ASD often communicate, interact, behave and learn differently, the CDC says. ASD symptoms typically begin before age 3 and can last a lifetime, although symptoms may change over time.
“There can be differences in how one is reading social cues and interpreting them, and then there’s also certain behaviors that we see,” Dr. Anna Krasno, clinical director of the Koegel Autism Center at the University of California, Santa Barbara, told ABC News.
“So those include a preference for sameness, a difficulty with transitioning, some cognitive and behavioral rigidity,” she continued. “We also see intense interests, so topics that people are super, super into and want to research, repetitive speech and motor movements. And then we also see really significant sensory differences as well.”
ASD is a spectrum, which means symptoms vary by person — some need little support in their daily lives and some may need a great deal of support in performing day-to-day activities. Some may have advanced conversation skills and others may be nonverbal.
Wider recognition, better understanding
Experts told ABC News there is a wider recognition and a better understanding of what is now understood as autism/ASD.
Traits of what is now known as ASD are built on early observations in the 1940s from Austrian-American psychiatrist Dr. Leo Kanner and Austrian physician Dr. Hans Asperger.
A 1943 paper from Kanner described 11 children who presented with “inborn autistic disturbances of affective contact” while Asperger’s 1944 report focused on boys who had marked social difficulties; unusual, circumscribed interests; and good verbal skills.
It was not until 1978 that autism was recognized as a developmental disorder distinct from schizophrenia by the World Health Organization. It was also in the 1970s that psychologists and psychiatrists first came to describe autism as a spectrum.
“When autism was first described, it was new to people understanding that there was a condition that included social communication difficulties and restricted and repetitive behavior, and people primarily only recognized it when it was at its most extreme,” Dr. Jeremy Veenstra-VanderWeele, division director in child and adolescent psychiatry at Columbia University, told ABC News.
“And so, if you go back and read the initial descriptions today, those are kids who we would recognize in the waiting room, recognize in the grocery store, in whom autism would be very obvious and would not require much assessment in order to diagnose,” he continued.
Better diagnostic tools
Experts say another reason for the increase in rates is having better diagnostic tools than what was available decades ago.
There is no single tool used as the basis of an ASD diagnosis. Typically, tools rely on descriptions from parents or caregivers of a child’s development and a professional’s observation of a child’s behavior, according to the CDC.
Currently, the Autism Society encourages all children to be screened for signs of autism by their family pediatrician three times by the age of three — at nine, 18, and 24 or 30 months. If a child shows symptoms of ASD, more rigorous diagnostic testing can be carried out by a specialist including a full neuropsychological exam.
Additionally, the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) provides standard criteria for helping diagnose autism.
Under DSM-5, a child meets the criteria if they have deficits in three areas of social communication and interaction and at least two of four types of restricted, repetitive behaviors.
While the first edition of DSM came out in 1952, it was not until the third edition, DSM-3, in which autism was listed under an entirely new “class” of conditions — the Pervasive Developmental Disorders.
Veenstra-VanderWeele said the change in the criteria is another reason why the number of those diagnosed with autism rose. He likened it to changing the definition of what it means to be tall.
“To just use a crude example, if you would define somebody as tall if they were over six-foot-six, and then 30 years later, say that somebody is tall if they’re over five-foot-10, you’d get very, very different numbers, and that’s part of what’s happened here,” he said.
Pierce added that because of limited knowledge and awareness in the past, there may have been many children who were underdiagnosed and misdiagnosed.
“It’s understandable that people wouldn’t even necessarily think that somebody has autism, because nobody knew what really autism was,” she said. “So, you know, large numbers of people were just put in the books as just having special education needs, maybe as a language delay or of having a cognitive impairment.”
Older reproductive age
Some studies have suggested that people who become pregnant at an older age have an increased risk of giving birth to a child with autism.
A 2012 review and meta-analysis of 16 papers from researchers in New York, London, Israel and Sweden found an association between advanced maternal age and the risk of autism.
Advanced paternal age may also be a risk factor. A 2006 study conducted jointly by researchers in New York, London and Israel found that men who were above age 40 were 5.75 times more likely to have a child with ASD compared to men younger than age 30 after controlling for other factors.
However, questions still swirl about whether or not there is a risk from the age of parents, and not all researchers are convinced.
“I know that there is some research looking at maternal and paternal age with regard to autism, and there’s research around environmental causes,” Krasno said. “I think where I always firmly land is that it is inherited, and it is genetic. So, I don’t know the exact correlation between age and diagnostic rate, but we do know that genetics are highly associated with diagnosis.”
Environmental risk factors
Researchers are also divided over whether or not environmental risk factors play a role in causing autism.
The National Institute of Environmental Health Sciences says the “clearest evidence” involves events before and during birth, including prenatal exposure to air pollution or pesticides; maternal obesity or diabetes; extreme prematurity; and periods of oxygen deprivation to the brain during birth.
“But these factors alone are unlikely to cause autism. Rather, they appear to increase a child’s likelihood for developing autism when combined with genetic factors,” NIEHS states on its website.
Pierce said from the studies she’s read, evidence suggests autism is a genetic condition. She added the environmental factors may play a role but “to a small degree.”
Myth that vaccines cause autism
The myth that vaccines cause autism was born out of a fraudulent 1998 study, hypothesizing that the measles, mumps, rubella vaccine caused intestinal inflammation, which, in turn, led to the development of autism.
The paper has since been discredited by health experts, retracted from the journal in which it was published, and its primary author, Andrew Wakefield, lost his medical license after an investigation found he had acted “dishonestly and irresponsibly” in conducting his research.
More than a dozen high-quality studies have since found no evidence of a link between childhood vaccines and autism.
However, Kennedy has held fast to this claim, saying during a 2023 interview on Fox News that he believes autism comes from vaccines.
During the HHS confirmation hearings, Kennedy said he was not “anti-vaccine” but “pro-safety.” At the same time, Kennedy repeatedly refused throughout the hearings to say that vaccines were not linked to autism, while still insisting he supports vaccination in general.
Experts told ABC News there is no evidence to suggest a link between vaccines and autism, and perpetuating the myth can be dangerous.
“Once there’s a lie and it’s spread, it doesn’t matter that it’s a lie. Once people hear it, then they believe that it’s true despite all of the Herculean efforts to disprove it and debunk it,” Pierce said. “There’s no evidence for it whatsoever, and there’s actually extremely, as far as scientific evidence is concerned, there’s extremely strong evidence to suggest absolutely not.”
Christopher Banks, president and CEO of the Autism Society of America, said the false claim that vaccines cause autism can divert financial resources from much-needed research.
“Instead of advancing support and therapies, time and funding are wasted disproving a debunked theory,” he said. “This misinformation also fuels stigma, implying that autism is something to be feared rather than understood and supported, leading to discrimination against autistic individuals.”
ABC News’ Dr. Jade Cobern, Cheyenne Haslett and Will McDuffie contributed to this report.
