Is the flu vaccine preservative harmful?

Thimerosal is a mercury-containing preservative that has been used in some vaccines for decades. It is no longer used in most childhood vaccines, but it may still be found in some flu vaccines.

The safety of thimerosal has been extensively studied, and there is no evidence that it causes any harm at the levels used in vaccines.

The World Health Organization (WHO) has stated that there is "no convincing evidence that would suggest any risk to health from the use of thimerosal-containing vaccines."

The Centers for Disease Control and Prevention (CDC) also states that "there is no link between thimerosal in vaccines and the development of autism."