Thimerosal's Safety Record Under Scrutiny Again, Despite Existing Evidence

Strategic Insights -

A century-old safety concern about bacterial contamination in vaccines led to the introduction of thimerosal, a preservative that has been a focus of debate in recent years. The US Centers for Disease Control and Prevention has scheduled a meeting to discuss thimerosal in vaccines, despite overwhelming evidence supporting its safety. Public health experts are puzzled by the decision, given the existing science and the concerns about the potential introduction of bias into the discussion.

Key Takeaways:

  • Thimerosal was introduced in the 1930s as a preservative to prevent microbial growth in vaccines, and it was used until the 1990s when concerns about its mercury content arose.
  • The FDA and CDC have removed thimerosal from all but a few vaccines, including multidose vials of flu vaccine, after questions emerged about its potential neurotoxicity.
  • Subsequent studies have confirmed no link between thimerosal in vaccines and neurodevelopmental issues, including autism, and autism rates have continued to rise despite the removal of thimerosal from most vaccines.
  • The presentation at the CDC meeting is scheduled to propose recommendations for thimerosal in flu vaccines, which could lead to official CDC policy if adopted by the agency.
  • Public health experts are concerned that the inclusion of thimerosal on the agenda is a red flag, given the existing science and the potential for bias in the discussion.
  • A parent who is presenting on the topic, Lyn Redwood, has previously claimed that thimerosal presents safety risks and has spoken at events and published papers about thimerosal and autism.
  • The CDC has posted its own review of the data, citing nearly two dozen studies showing no link between thimerosal-containing vaccines and autism spectrum disorder or other neurodevelopmental disorders.

Statistics:

  • By 2001, thimerosal had been removed from or reduced in all vaccines routinely recommended for children under 6 in the US, according to the CDC.
  • Nearly two dozen studies have found no link between thimerosal-containing vaccines and autism spectrum disorder or other neurodevelopmental disorders.
  • Autism rates have continued to rise despite the removal of thimerosal from most vaccines.
  • Multidose vials of flu vaccine remain the only vaccines that still contain thimerosal in the US.

Sources:

  • US Centers for Disease Control and Prevention (CDC)
  • US Food and Drug Administration (FDA)
  • The American Academy of Pediatrics (AAP)
  • CNN's Brenda Goodman
  • The Institute of Medicine (now known as the National Academy of Medicine)
  • The University of Rochester
  • The National Environmental Health Association (NEHA)
  • The Children's Health Defense organization