CDC Launches Study on Vaccine-Autism Link Amid Ongoing Measles Outbreak

The CDC is set to initiate a large study investigating the belief that vaccines cause autism spectrum disorder (ASD). Although decades of research have demonstrated there is no link, there remain some in the public who continue to have doubts. The decision has sparked significant debate among health experts, agency heads, and the US public at a time when vaccine hesitancy and medical mistrust has peaked.¹

CDC office in Atlanta, Georgia | Image Credit: © Tada Images - stock.adobe.com

The CDC’s decision to launch a vaccine-ASD study comes amid a growing measles outbreak that originated in West Texas and has since spread to other states, including New Mexico and Oklahoma, as well as New Jersey, Ohio, Washington, and more. As of March 21, 2025, the total number of reported cases has risen to 321, of which 279 are in Texas alone. The outbreak has also resulted in 2 deaths. According to the Texas Tribune, public health experts believe the outbreak is on track to lead to a national epidemic.^2,3

Vaccination with the mumps, measles, and rubella (MMR) vaccine is the best protection against measles infection; however, vaccine hesitancy continues to persist, causing some to avoid vaccination to prevent measles for themselves and their dependents. For these individuals, trust in science, medicine, and the health care system is low, supporting suspicions around vaccine safety.

“It is, in my opinion, a waste of federal resources to actually reconduct and relitigate this issue between the link between MMR vaccine, particularly, and autism, or the use of numerous vaccines together in the childhood schedule and autism,” Michael Hogue, PharmD, FAPhA, FNAP, FFIP, executive vice president and chief executive officer of the American Pharmacists Association, said in an interview with Pharmacy Times®.

In an interview with former United States Surgeon General Jerome Adams, MD, MPH, FASA, he expressed his cautious optimism on reigniting public trust in vaccination, so long as the CDC’s study is effectively designed.

“The overwhelming consensus in the scientific community is that vaccines don't cause autism, but it's also undeniable that lingering public questions and concerns still do exist,” he said. “This initiative if—and I want to emphasize the if here—done thoughtfully and without any agendas, could help reaffirm the safety of vaccines, could help reassure patients, and could ultimately strengthen public trust and immunization programs.”

Danielle L Stutzman, PharmD, BCPP, a psychiatric pharmacist at the Pediatric Mental Health Institute at Children’s Hospital Colorado, shared her own concerns, citing the study's potential to perpetuate stigmatization of vaccines and, in particular, ASD.

"Recent studies suggest significant reductions in vaccine hesitancy among patients with autism, increased rates in vaccine schedule compliance, and reduced beliefs that there is a link between vaccines and autism," she explained. "Reevaluating the link between vaccines and autism, a phenomenon that is well studied and debunked, introduces risk of reigniting stigma and fear among this vulnerable patient population."

Do vaccines cause autism?

The belief that vaccines cause ASD started in 1998 when Andrew Wakefield and his colleagues published a paper in The Lancet concluding a direct causal link between the combined MMR vaccine and the onset of developmental delays. However, this study was redacted by the journal due to multiple reports of misconduct and conflicts of interest, namely the funding of the study by lawyers acting for parents who were involved in lawsuits against vaccine manufacturers.⁴

“I can remember when the Wakefield study was first published in The Lancet, and the uproar that happened when it was discovered that Andrew Wakefield had falsified all of the data that they used to publish the article,” recalled Hogue.

Mother painting with daughter with autism spectrum disorder | Image Credit: © Alexis Scholtz/peopleimages.com - stock.adobe.com

Government and health agencies across the world have dedicated millions of dollars to studies investigating vaccines and ASD and consistently found no link. However, as rates of ASD “increase,” the findings of the Wakefield study persist among the public. Clinical understanding of ASD is ever evolving, leading to improved diagnostics and, thereby, an increase of cases of ASD. However, rising cases is not necessarily indicative of a correlation; rather, it is representative of the medical advancements that allow for better diagnostics for the disorder.

If vaccines do not cause ASD, what does? ASD has no single cause and is believed to be a result of multiple factors. Studies have found strong evidence of the interplay between genetic and environmental factors in the development of ASD. In a meta-analysis of 7 twins, researchers found that 60% to 90% of ASD risk comes from genomes.^5,6

“When you look at the increase in additives to foods, in dyes, in toxins in our environment and in the air, there are so many other more plausible mechanisms for our increase in [ASD] than vaccines,” explained Adams.

What are the implications of the CDC launching a vaccine-ASD study?

The CDC’s decision to revisit the vaccine-ASD question carries significant consequences for public perception, health policy, and vaccine uptake. Although some experts hope the study will provide a definitive reaffirmation of vaccine safety and restore public trust, others worry the launch of such a study in and of itself may inadvertently support concerns, further fueling skepticism around the safety of vaccines. Such a study could provide new momentum to the anti-vaccine movement, potentially undermining immunization efforts at a time when outbreaks of preventable diseases, like measles, are on the rise.

There is also the concern that the study could divert critical resources from more pressing public health initiatives, such as improving vaccine access and addressing the social determinants of health that contribute to vaccine hesitancy. Some experts argue that continued investment in vaccine education and outreach would be more effective than re-examining a question that has already been extensively studied.

Stigmatization of ASD is an ongoing challenge that could be exacerbated by improper reporting of study findings and misinterpretation of the findings by the public. This could further marginalize individuals with ASD, while also fueling vaccine hesitancy, potentially leading to lower immunization rates and increased outbreaks of preventable diseases.

“A concern that I have is that we're stigmatizing and demonizing [ASD],” said Hogue. “So, it's vital the CDC, if they do this study, communicates its findings clearly and responsibly and as an underpinning, emphasizes the safety and efficacy of vaccines.”

Mother holding child saying no to vaccine | Image Credit: © - stock.adobe.com

Ultimately, the impact of the study will depend not only on its findings but also on how they are framed and disseminated to the public. Clear, transparent, and scientifically grounded communication will be essential in ensuring that the study reinforces confidence in vaccines rather than further eroding it.

“So, it's vital the CDC, if they do this study, communicates its findings clearly and responsibly and as an underpinning, emphasizes the safety and efficacy of vaccines,” said Adams.

How can pharmacists address vaccine hesitancy?

Vaccine hesitancy is complex and multifactorial. It is impacted by safety concerns, lack of trust, as well as religious and cultural beliefs. Addressing this issue requires a compassionate approach based in scientific evidence that does not shame individuals who are vaccine hesitant. Health care providers, especially pharmacists, are well positioned to help educate and inform patients of the safety and importance of vaccinations, especially against measles and other highly infectious viruses.⁷

“We can't make people feel like they're wrong or they're bad people, [or that] they're ignorant for asking the question. I think we've done too much of that,” advised Adams. “I think now is the time for us as a broader community supportive of public health to rethink the way that we're communicating and engaging with the public and to do it in a more empathetic way.”

Building trust and fostering open dialogue are key to addressing vaccine hesitancy, according to Adams. Rather than dismissing concerns outright, pharmacists and other health care providers can take the time to listen, acknowledge fears, and provide credible, evidence-based information. Meeting patients where they are and engaging in respectful conversations can help bridge gaps in understanding and encourage informed decision-making.

“Pharmacists have to determine where's this person is coming from? Try putting yourself in the person's shoes and understand why they have that perspective,” said Hogue. “You can share the science and, hopefully, point someone in a direction where they'll read legitimate science and not just sensationalized stuff on social media.”

As vaccine hesitancy persists, health care professionals must work together to ensure that accurate information reaches the public in accessible and engaging ways. Stutzman highlighted the critical role psychiatric pharmacists play in addressing patients' concerns, particularly when it comes to autism and vaccines. By working alongside child psychiatrists and pediatricians, psychiatric pharmacists are well-positioned to provide valuable insights and guidance to caregivers.

"Psychiatric pharmacists, as partners with child psychiatrists and pediatricians, play an important role in addressing concerns or questions related to autism and vaccines," she said. "Pharmacists, including psychiatric pharmacists, receive training on the benefits, risks, and pediatric-specific schedules for vaccine administration. All pharmacists are equipped to help caregivers separate fact from fiction where vaccine safety is concerned."

The CDC’s study comes at a critical moment for public health, with vaccine hesitancy on the rise and preventable diseases resurfacing. Although some see this as an opportunity to reaffirm vaccine safety, others worry it could give undue weight to long-debunked fears. How the findings are communicated will be just as important as the results themselves—clear, responsible messaging will be essential to prevent further erosion of trust in vaccines and to avoid deepening the stigma surrounding ASD.

REFERENCES

1. Exclusive: US CDC plans study into vaccines and autism, sources say. Reuters. March 9, 2025. Accessed March 21, 2025. https://www.reuters.com/business/healthcare-pharmaceuticals/us-cdc-plans-study-into-vaccines-autism-sources-say-2025-03-07/

2. Over 300 measles cases reported in the U.S., officials say. CBS News. March 21, 2025. Accessed March 21, 2025. https://www.cbsnews.com/texas/video/over-300-measles-cases-reported-in-the-u-s-officials-say/

3. Texas is poised to make measles a nationwide epidemic, public health experts say. The Texas Tribune. March 21, 2025. Accessed March 21, 2025. https://www.texastribune.org/2025/03/21/texas-measles-vaccine-new-mexico-oklahoma-us/

4. Eggertson L. Lancet retracts 12-year-old article linking autism to MMR vaccines. CMAJ. March 9, 2010. doi: 10.1503/cmaj.109-3179

5. Tick B, Bolton P, Happé F, et al. Heritability of autism spectrum disorders: a meta-analysis of twin studies. J Child Psychol Psychiatry. 2016. doi:10.1111/jcpp.12499

6. Karimi P, Kamali E, Mousavi SM, Karahmadi M. Environmental factors influencing the risk of autism. J Res Med Sci. February 16, 2017. doi: 10.4103/1735-1995.200272

7. Kumar S, Shah Z, Garfield S. Causes of vaccine hesitancy in adults for the influenza and COVID-19 vaccines: A systematic literature review. Vaccines (Basel). September 13, 2022. doi: 10.3390/vaccines10091518