WASHINGTON, D.C.: The U.S. Centers for Disease Control and Prevention (CDC) is planning an extensive study on possible links between vaccines and autism, despite past research showing no connection, sources told Reuters.

This comes as the U.S. faces a significant measles outbreak, with over 200 cases and two deaths in Texas and New Mexico, partly due to declining vaccination rates.

U.S. Health Secretary Robert F. Kennedy Jr., who has questioned vaccine safety, recently discussed the outbreak but did not emphasize the role of vaccines in preventing measles.

He later published an opinion piece supporting vaccination while also calling it a personal choice. It is unclear if Kennedy is involved in the CDC study.

The CDC and the Department of Health and Human Services (HHS) cited rising autism diagnoses in a joint statement, saying they will investigate the issue thoroughly. Many experts believe the increase is due to better screening and broader diagnostic criteria, not vaccines. However, some public figures continue to promote the debunked claim that vaccines cause autism.

President Donald Trump recently addressed the rise in autism and expressed support for Kennedy's efforts to investigate it. Meanwhile, Trump's nominee for CDC director, Dr. Dave Weldon, faces scrutiny over his views on vaccines. Some lawmakers worry that a government-led study, even without evidence, could further spread doubt about vaccines.

Autism diagnoses in the United States have increased significantly since 2000, intensifying public concern.

Many researchers attribute the rise in diagnoses to more widespread screening and the inclusion of a broader range of behaviors to describe the condition. But some public figures have popularized the idea that vaccines are to blame, an idea stemming from a since-debunked study from British researcher Andrew Wakefield in the late 1990s that connected a rise in autism diagnoses with widespread use of the MMR shot.

This week, Cassidy questioned Trump's nominee to lead the National Institutes of Health, Dr. Jay Bhattacharya, over his stance on investigating a potential link between autism and childhood vaccinations.

"I don't generally believe there is a link, based on my reading of the literature," Bhattacharya said. "But we do have a sharp rise in autism rates, and I don't think any scientist really knows the cause of it. I would support a broad scientific agenda based on data to get an answer to that."