What is thimerosal, does it have side effects and why is RFK Jr. removing the controversial preservative from the flu shot?

Although it has been largely phased out of U.S. vaccines, thimerosal has long been targeted by anti-vaccine advocates.

The federal government is recommending flu vaccines remove the preservative thimerosal after Health and Human Services ...

Following a recommendation from a panel of CDC advisors, HHS Secretary Robert F. Kennedy Jr. on Wednesday ordered that the ...

The mercury-based ingredient has prompted concerns from some organizations, although the CDC has said there is no evidence it ...

Health and Human Services Secretary Robert F. Kennedy Jr. has signed off on a recommendation to remove thimerosal from all ...

Antivaccine activists have long linked the ingredient to autism; the CDC says there is no evidence of harm.

Secretary Robert F. Kennedy Jr. | HHS Secretary Robert F. Kennedy Jr. has signed off on a recommendation from an advisory ...

The move targets thimerosal, a preservative that anti-vaccine activists blame for neurodevelopmental disorders, despite ...

While few shots still contain thimerosal, the move eliminates a vaccine option for Americans and is a win for the ...

RFK Jr. approves a nationwide shift to mercury-free flu vaccines, ending decades of thimerosal use amid rising safety and ...

Banning vaccine ingredients without cause increases the perceived risk of vaccines," one prominent health group said.