The United Nations backed down from a ban on a vaccine preservative that could have driven up prices and required a complex network of cold storage facilities.Thimerosal was spared from a U.N. mercury treaty.
Scientists and vaccine manufacturers have added the organic mercury compound thimerosal to multidose vaccines since the 1930s, a mainstay for the developing world. And despite groups of experts--including the Institute of Medicine, the American Academy of Pediatrics, the U.K.'s Committee on Safety of Medicines and the European Agency for the Evaluation of Medicinal Products--concluding that the compound is safe and effective, the United Nations Environment Program still considered adding the product to a treaty on the release of mercury into the environment.
"Thimerosal remains an important vaccine preservative in resource-poor countries," experts wrote in the journal Pediatrics. "Thimerosal allows the use of multiuse vials, which reduce vaccine cost and the demand on already constrained cold-chain systems. Even in the United States, thimerosal could be critical for dealing with emergencies and the need to rapidly increase vaccine supply and delivery, such as during a serious pandemic of influenza."
Researchers say making a vaccine without the preservative could cost anywhere from two to 5 times as much, and keeping vaccines refrigerated would cause a spate of logistical and financial issues.
The multidose presentation of CSL Limited's Afluria and multidose formulations of Sanofi Pasteur's Fluzone and Novartis' ($NVS) Fluvirin all contain the preservative. Still, some advocacy groups argue that there's a link between thimerosal and autism in children. Multiple studies knock down this theory.
The Study on Global AGEing and Adult Health (SAGE) last April went so far as to say replacing the preservative could affect the quality, safety and effectiveness of a vaccine. The World Health Organization quoted the group as saying, "[Thimerosal]-containing vaccines are essential and irreplaceable components of immunization programs, especially in developing countries."
More than 140 countries and 900 delegates participated in the U.N.'s final decision to exclude thimerosal from the treaty.