Vaccine Myth #8: A Preservative Contained in Many Vaccines Harms Children

In 1999, a study revealed that the preservative thimerosal, a mercury-containing compound present in many vaccines, caused several infants to have levels of mercury in their blood that exceeded guidelines recommended by the Environmental Protection Agency (EPA). Preservatives are used in vaccines to reduce the risk of contamination by bacteria once the vial is opened. Exposure to high levels of mercury, especially in the developing child before birth, is associated with neurological disturbances. Therefore, parents began to fear that thimerosal may cause neurological difficulties, like autism. When this study was first described, physicians, scientists, and public health officials quickly assessed the situation and found that:

  • the levels of mercury did not exceed guidelines recommended by the Food and Drug Administration (FDA), the agency responsible for the safety of drugs and biologics (such as vaccines);
  • vaccines containing thimerosal have been used since the 1930s, and no child has ever been proven to have been harmed by trace amounts of thimerosal in vaccines;
  • thimerosal contains ethyl mercury, not methyl mercury (the most harmful form of mercury); and
  • mercury is eliminated from the body within two months, an interval commonly used to administer vaccines.

Even though the FDA and CDC concluded that thimerosal was safe for infants, they feared that vaccines containing thimerosal would be perceived as unsafe by the public. Therefore, in 1999, the CDC recommended that thimerosal be removed from vaccines as quickly and efficiently as possible.

Since the thimerosal was removed from vaccines, autism rates have NOT decreased, but increased.

Today, all vaccines on the recommended childhood immunization schedule appear in either a thimerosal-free form or a form of thimerosal that is reduced by greater than 95 percent.

You can read more about vaccine myths in my book God’s Design for the Highly Healthy Child.

For more information on thimerosal from the CDC, click here. Also, see my previous blogs on thimerosal:

Here are other blogs in this series you might find useful: