Pediatricians’ statement on thimerosal in vaccines

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Guest blogger Harold DeMonaco submitted this column:

“They are DANGEROUS when they get together and do a little thinking!”

That’s a quote from an anonymous posting in response to a MedPage Today story on today’s American Academy of Pediatrics endorsement of a Recommendation of WHO Strategic Advisory Group of Experts (SAGE) on Immunization to allow the use of thimerosal as a preservative in vaccines. Here is what the Academy said:

“The American Academy of Pediatrics endorsed the recommendation of the World Health Organizations Strategic Advisory Group of Experts (SAGE) on Immunization pertaining to the use of thimerosal in vaccines. The recommendation can be found on pages 215216 here. The Pediatric Infectious Diseases Society and the International Pediatric Association have also endorsed this recommendation.”

The World Health Organization rationale is pretty straightforward.  Immunization is arguably one of the most important public health measures available.  Thousands of children die as a result of preventable illness and a lack of available vaccine.  There is a critical shortage of non-thimerosal containing vaccines in the developing world thus limiting the availability of vaccines.  Despite its negative points, thimerosal is a good preservative and allows vaccines to be administered from multiple dose vials.  This lowers costs and reduces the likelihood of cross contamination.  The ability of the developing world to absorb the added costs of non-thimerosal containing vaccines is limited.  According to the WHO guidance:

“Replacement of thimerosal with an alternative preservative may affect the quality, safety, and efficacy of vaccines; re-registration would be required by the National Regulatory Authority in each jurisdiction where a reformulated product was intended to be used; currently available alternative preservatives interacted in unpredictable ways with existing vaccines, and there are no consensus alternative preservatives for the near- or mid-term.”

So, has the WHO decision unnecessarily exposed children to the risks of thimerosal?  Just to be clear, here is what the FDA said in an article published in Pediatrics (Pediatrics. 2001 May;107(5):1177-8; PMID: 11331704) :

“Our review revealed no evidence of harm caused by doses of thimerosal in vaccines, except for local hypersensitivity reactions. However, some infants may be exposed to cumulative levels of mercury during the first 6 months of life that exceed EPA recommendations. Exposure of infants to mercury in vaccines can be reduced or eliminated by using products formulated without thimerosal as a preservative.” (emphasis added)

Interpretation:  This was a precautionary process.  There is no evidence of harm but if thimerosal can be eliminated we should do so.  In response, the pharmaceutical industry reformulated the majority of vaccines that contained thimerosal.  Reformulation requires a host of changes and validations.  An expensive and time consuming process.  You can view the list of reformulated and FDA approved vaccines here.

The endorsement by the American Academy of Pediatrics does not alter the formulation of products in the United States.  It does not endorse thimerosal but rather recognizes the issues in the developing world related to vaccine cost and availability.  Is it better to not have a potentially toxic material in the vaccines?  Of course it is.  But is it better to not have the vaccine at all for children in the developing world at all?

The predictable outcry has already started as exemplified by a comment in response to the MedPage Today article:

It’s official! The American Academy of Pediatrics no longer has children’s health and well-being as a primary focus. This neurotoxin is NOT safe in ANY amount and should not be in ANY vaccine or other medication. There has NEVER been a study done where thimerosal was injected into any lab animal where the result wasn’t brain damage. What would make anyone think this isn’t happening to our children? According to the CDC, one in six children in the US has a developmental disability and 1 in 88 has autism! If this is the best the AAP can do, clearly they need to just disband! They are DANGEROUS when they get together and do a little thinking! Actually it is clear they are thinking with their Pharma- stuffed wallets!

A review paper was published in 2010 (Shultz S. Does thimerosal or other mercury exposure increase the risk for autism? Acta Neurobiologiae Experimentalis. 70(2):187-95, 2010) concluded:

The evidence presented here does not support the association between autism and mercury exposure from the pharmaceutical preservative thimerosal.  The evidence is equivocal for an association between other environmental exposures with autism. “

Here is a list of the vaccines recommended for children up to six and their thimerosal status:

DTaP- thimerosal removed in 2001

Hepatitis A vaccine never contained thimerosal

Rotavirus vaccine never contained thimerosal

Haemophilus influenza type B – thimerosal removed in 1999

Pneumococcal Vaccine never contained thimerosal

Inactivated polio virus never contained thimerosal

Influenza vaccine-most never contained thimerosal

Measles, mumps and rubella never contained thimerosal

Varicella never contained thimerosal

Hepatitis A never contained thimerosal

No routine childhood vaccine has contained thimerosal since 2001.  Perhaps more of us need to “get together and do a little thinking.”


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Comments (4)

Please note, comments are no longer published through this website. All previously made comments are still archived and available for viewing through select posts.


December 19, 2012 at 10:41 pm

Hi Gary, the point of the AAP and WHO recommendation is that children in developing countries need vaccines and thimerosal is a safe and inexpensive ingredient. There is no reason to remove it. Thus, they support leaving it in. It was all but removed from vaccines in the USA only because of media hype, not because there was actually anything wrong with it.

Victoria Van Roy

December 24, 2012 at 11:04 am

All multidose influenza vaccines have thimerasol