A panel tasked with advising the Centers for Disease Control and Prevention on vaccine policy recommended Thursday that makers of flu vaccines should remove a well-studied ingredient used as a preservative, capitulating to anti-vaccine advocates who falsely claim it causes autism.

Most flu vaccines already do not contain the ingredient, thimerosal, but it is still used in multi-dose vials to prevent bacterial contamination when multiple needles are inserted.

The panelists were hand-selected by Robert F. Kennedy Jr., the nation’s health secretary who is best known for spreading conspiracy theories about vaccines and public health. Kennedy had fired all 17 members of the Advisory Committee on Immunization Practices earlier this month.

Thimerosal has been in use in medicine for nearly a century. It has repeatedly been studied and found to be harmless, but skeptics point to the fact that it contains a very small amount of a type of mercury.

Hoping to put parents’ minds at ease, the CDC asked pharmaceutical companies in 1999 to remove thimerosal from vaccines out of an abundance of caution. But critics of that decision argue that it spread mistrust by suggesting thimerosal was harmful.