For the second time in a year, the Centers for Disease Control and Prevention updated a key page on its website about autism and vaccines, doubling down on the idea that the science is unsettled.

The agency tweaked its “autism and vaccines” webpage last week in a bid to appease U.S. Sen. Bill Cassidy, R-La., the chair of the Senate’s Committee on Health, Education, Labor and Pensions. But even he says that the information on the page remains problematic.

Up until last November, the page had indicated that “studies have shown that there is no link between receiving vaccines and developing autism.” At that point, the page was altered to read “The claim ‘vaccines do not cause autism’ is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.”

Still, a header on the page continued to say “vaccines do not cause autism.” The statement was appended with a notation to indicate that the header had only been retained to honor an agreement with Cassidy.

As of last week, the reference to Cassidy is no longer. Instead, the note indicates “Scientists have not identified the root causes of autism. HHS continues to support rigorous scientific research and will update this page as reliable new evidence becomes available.” Everything else on the page is unchanged.

Cassidy said the CDC made the update as a “sign of good faith” in an effort to win his support for the current nominee to lead the agency, Dr. Erica Schwartz. The senator cited the move in announcing that he has agreed to back her nomination.

Still, however, Cassidy told CNN this weekend that while “there’s been some progress made,” serious concerns remain with the CDC webpage.

“It’s wrong because it’s going to frighten some parents from doing the right thing, which is to have their child vaccinated,” Cassidy said. “It’s been firmly established — vaccines do not cause autism. That’s over decades. The fact that that is still there is almost an insult to the American people.”

The changes to the CDC autism and vaccines page have also drawn concern from experts in the field.

“The information posted by the CDC is extremely disturbing,” said Helen Tager-Flusberg, director of the Center for Autism Research Excellence at Boston University, who’s leading the Coalition of Autism Scientists, a group of more than 300 researchers in the field. “It misrepresents the evidence and all but claims that vaccines cause autism. It is simply false to say that scientists don’t know what causes autism. We know a great deal about its causes — primarily genetics.”

Officials with the CDC and the Department of Health and Human Services did not respond to requests for comment about the recent website update.