The American Academy of Pediatrics has announced its endorsement of the World Health Organization's (WHO) recommendation that thimerosal not be banned from vaccines.
The preservative, which contains ethyl mercury, has been used in some vaccines since the 1930s as an antibacterial and antifungal agent, according to a commentary published online Dec. 17 in the organization's official journal, Pediatrics.
According to the authors, the United Nations Environmental Program (UNEP) is developing an international treaty aimed at eliminating controllable mercury pollution and exposure throughout the world due to well-known toxic effects. As part of the treaty, UNEP is considering recommending the removal of thimerosal.
In the statement, the authors distinguish between toxic methyl mercury and the ethyl mercury in thimerosal. They say that although methyl mercury has demonstrated clear toxic effects, studies over the past 15 years have failed to link the use of ethyl mercury to similar serious neurodevelopmental disorders.
The Academy says the use of thimerosal allows the use of multiuse vials, which would reduce the cost of vaccines; global removal could adversely affect the worldwide vaccine supply.
A WHO Strategic Advisory Group of Experts on Immunization recently recommended that the portion of the UNEP treaty specifying thimerosal be removed, the authors state, adding that they agree.
The authors say they strongly support global immunization efforts. Immunization prevents approximately 2.5 million deaths a year globally, and, if strengthened, could prevent millions more.
"The preponderance of available evidence has failed to demonstrate serious harm associated with thimerosal in vaccines. As such, we extend our strongest support to the recent Strategic Advisory Group of Experts recommendations to retain the use of thimerosal in global vaccine supply," the authors write.