thimerosal, a preservative used in vaccines, should be further assessed for safety, say researchers from the University of California-Davis in the us. In a study conducted on mice, they found that the chemical may alter the response of dendritic cells (part of the immune system) to biochemical signals.
An ethylmercury-based compound, thimerosal has been linked to the rising incidence of autism. Besides, there have been indications that it could be toxic to the immune system, but its specific targets were not known. For the study, the researchers grew dendritic cells from the bone marrow of mice in lab and treated them with thimerosal. They found that thimerosal in concentrations as low as 20 parts per billion (ppb) altered the activity of dendritic cells, and concentrations above 200 ppb caused immature dendritic cells to die. The study was published in Environmental Health Perspectives (Vol 114, No 7).
The study comes at a time when a bill, Vaccine Safety and Public Confidence Assurance Act of 2006, has been introduced in the us Congress demanding that responsibility for vaccine safety be taken away from the Centers for Disease Control and Prevention for saying that the use of mercury in vaccines is safe. Thimerosal has been removed from most vaccines used for children, but is still used in some flu vaccines.
The scientists, however, say the study does not directly implicate thimerosal as a single causative agent for triggering neurodevelopmental disorders such as autism.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
.png)
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.