The CDC is reportedly planning a large-scale study examining autism prevalence and potential contributing factors, according to two sources familiar with the matter. Previous large-scale epidemiological studies and meta-analyses have found no causal association between vaccines and autism.
It is unclear whether U.S. Health Secretary Robert F. Kennedy Jr., who has previously raised concerns about vaccine safety, is involved in the planned CDC study. The CDC and the Department of Health and Human Services have not provided official comment.
The CDC’s initiative comes amid one of the largest measles outbreaks in the U.S. in the past decade, with over 150 cases and two fatalities reported in Texas and New Mexico. Declining vaccination rates in some regions have contributed to the outbreak.
Kennedy, whose role includes oversight of the CDC, has previously questioned the safety of the measles, mumps, and rubella (MMR) vaccine. At a recent cabinet meeting, Kennedy referred to a measles-related pediatric fatality in Texas as part of routine disease patterns and did not reference vaccination in his remarks.
Autism diagnoses in the U.S. have increased significantly since 2000. Research attributes this trend primarily to changes in diagnostic criteria, increased awareness, and expanded screening practices. Studies suggest that autism’s neurodevelopmental features arise in utero, potentially influenced by genetic and prenatal environmental factors. No rigorous study has established a link between autism and childhood vaccinations, vaccine preservatives, or other vaccine components.
During Kennedy’s confirmation hearing, Senator Bill Cassidy, MD (R-LA), asked whether he would disavow claims of a connection between vaccines and autism. Kennedy stated that he is not opposed to vaccines but did not comment on past claims about such a link.
This week, Senator Cassidy also questioned Dr. Jay Bhattacharya, President Donald Trump’s nominee to lead the National Institutes of Health, about his stance on the potential relationship between autism and vaccines. Bhattacharya stated that while he does not believe there is a link based on his review of the literature, further research is needed to better understand the causes of rising autism diagnoses.
