United Nations mercury treaty jeopardizes vaccine protection of the world's most vulnerable children

[Extract] Thiomersal (also known as thimerosal in the United States) is a bacteriostatic preservative used in vaccines and other biologic products since the 1930s for several specific reasons: as a broad bacteriostatic agent; as a preservative; and to inactivate specific moieties. Its concentration in most vaccines results in delivery of about 25 μg of thiomerosal in each dose administered. Importantly, thiomerosal is only 50% ethylmercury by weight. Many regulators, including the United States Code of Federal Regulations, require the addition of a preservative to multi-dose vaccine vials. Multi-dose vials have several advantages. They are cheaper than single dose formulations, and because more doses can be stored in a smaller space, they allow for decreased storage costs across the cold chain from production to final administration. These costs can be quite substantial for large immunization programs