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18-12-2012 | Article

Organizations entreat United Nations not to ban thimerosal


AAP commentaries

medwireNews: The American Academy of Pediatrics (AAP) has endorsed the World Health Organization's (WHO) recommendation to remove a proposed ban of the vaccine preservative thimerosal, which contains ethyl mercury.

The United Nations Environmental Program's (UNEP) draft treaty to eliminate controllable mercury pollution and exposure throughout the world includes thimerosal, which the WHO and AAP view as having a very important role in maintaining vaccinations in resource-poor countries.

"The continued benefits of thimerosal use in vaccine manufacturing clearly outweigh any perceived risks," primary author Walter Orenstein, from the Rollins School of Public Health in Atlanta, wrote in an accompanying AAP commentary.

Thimerosal makes multiuse vials possible, lowering costs and demand on transportation and storage systems. The WHO has estimated that a thimerosal ban would increase the manufacturing costs of vaccines by 200% to over 500%, and force the production and distribution of single-dose vaccines - a switch that resource-poor nations cannot accommodate.

"Global removal of thimerosal has the potential to adversely affect the world-wide vaccine supply," Orenstein wrote, pointing out that immunization prevents approximately 2.5 million deaths per year globally.

During the 15 years since the AAP and the US Public Health Service (USPHS) originally recommended the removal of thimerosal, evidence has accrued that "overwhelmingly" shows that the use of thimerosal in vaccines does not impose significant harm. The Institute of Medicine has dismissed any link between thimerosal and neurodevelopmental disorders like autism.

In a related AAP commentary, Louis Zooper (Columbia University, New York) explained the 1999 ban of thimerosal as a response to a Food and Drug Administration review. At the time, immunizations were given to young infants from multidose vials according to a recommended schedule. The cumulative amount of mercury was found to potentially exceed US Environmental Protection Agency guidelines (but not those of two other US federal guidelines).

"The absence of clear data for ethyl mercury did not allow any assumption to be made about its safety," Zooper explained. "No studies evaluated the safety or potential harm from the amount of ethyl mercury in the US infant immunization schedule." USPHS and AAP recommendations always prioritize a "first, do no harm" philosophy, he added.

Zooper considered it impossible that a thimerosal ban would have been imposed if the current evidence was available to the AAP and USPHS 15 years ago. "The [WHO] recommendation… must be heeded or it will cause tremendous damage to current programs to protect all children from death and disability by vaccine-preventable diseases," he concluded.

By Peter Sergo, medwireNews Reporter