Issue: January 2013
Perspective from Richard F. Jacobs, MD
December 18, 2012
2 min read

AAP, experts in pediatrics support WHO statement on thimerosal in vaccines

Issue: January 2013
Perspective from Richard F. Jacobs, MD
You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

The AAP on Monday publically backed WHO’s Strategic Advisory Group of Experts’ recommendation to keep thimerosal in vaccines, rather than banning the substance entirely, as proposed in language from the United Nations Environment Programme.

In an accompanying editorial to the AAP statement, Infectious Diseases in Children Editorial Board member Walter Orenstein, MD, and colleagues said banning thimerosal could potentially drive up manufacturing costs and limit storage capabilities in parts of the world where refrigeration and single-dose vials could pose challenges.

This endorsement to retain thimerosal is a reversal of a 1999 call for removal of the preservative from vaccines by the AAP and the US Public Health Service (USPHS). Orenstein and others who were involved in the original decision to remove thimerosal from US vaccines said they would likely not have made the decision now that they made then because new data have come to light.

In 1999, thimerosal, which contains ethyl mercury, was removed from vaccines, despite very limited data linking it to autism. The limited connection, however, was enough to galvanize public beliefs in the connection.

In another accompanying editorial to the AAP statement, Louis Z. Cooper, MD, of Columbia University in New York, and Samuel Katz, MD, of Duke University in Durham, N.C., wrote that the thimerosal removal recommendation would likely not have taken place if the updated data on pharmacology and toxicology of ethyl mercury that is available now had been available in 1999.

“Had the AAP (and, we suspect, the USPHS) known what research has revealed in the intervening 14 years, it is inconceivable to us that these organizations would have made the joint statement of July 7, 1999,” Cooper and Katz wrote.

In a separate commentary, Katherine King, PhD, of St. Michael’s Hospital in Toronto, and colleagues added, “for low- and middle-income countries, where the burdens of vaccine-preventable deaths are most profound, multidose vials of thimerosal-preserved vaccines are a critical part of immunization programs.”

For more information:

AAP. Pediatrics. 2012;doi:10.1542/peds.2012-2262.

Cooper LZ. Pediatrics. 2012:doi: 10.1542/peds.2012-1823.

King K. Pediatrics. 2012;doi:10.1542/peds.2012-2976.

Orenstein WA. Pediatrics. 2012;doi:10.1542/peds.2012-1760.