IAS Complaint Part 1: Thimerosal in Your Vaccine? No.

By Darcy Cowan 11/10/2011

As promised here is the first of the articles that I deal with in the formal complaint I made to the Charities Commission regarding the misinformation spread by the anti-vaccine charity IAS.  So, with out further ado (what is ado anyway?) here is the link to the offending piece and my rebuttal:

Thimerosal in your Vaccine?
Posted September 13, 2010

This post on the IAS website (made up of basically an uninformed question about the harmfulness of ethyl mercury and a video) insinuates that Ethyl Mercury (also known under the trade name Thimerosal)1 is both harmful in the amount contained in vaccines and, by extension, that New Zealand vaccines contain this substance and should therefore be viewed with suspicion.

The first thing to note is that the Thimerosal post is irrelevant to New Zealand populations as Thimerosal is not present in any of the vaccines used in New Zealand2. Bringing up this issue in the context of New Zealand vaccines (implied as this is a New Zealand organisation geared towards New Zealand residents) is at best ignorant and at worse disingenuous scaremongering. Even so it is useful to deconstruct the post anyway as it is indicative of the faulty reasoning and scientifically inaccurate content of the IAS website.

The post includes a link to the Material Safety Data Sheet (MSDS) for Ethyl Mercury as support for this claim3. The relevant part of the MSDS has been reproduced below to give an indication of what the post considers concerning about the use of Thimerosal in vaccines.

Quoting from the MSDS:

’Effects of Overexposure: Topical allergic dermatitis has been reported. Thimerosal contains mercury. Mercury poisoning may occur and topical hypersensitivity reactions may be seen. Early signs of mercury poisoning in adults are nervous system effects, including narrowing of the visual field and numbness in the extremities. Exposure to mercury in utero and in children may cause mild to severe mental retardation and mild to severe motor coordination impairment.’

This is used in conjunction with a video link on the page4 to advance the hypothesis that Thimerosal in vaccines causes  autism, despite the fact that the symptoms listed are explicitly due to overexposure, not the trace exposure that  constitutes the vaccine dose. This type of ’any level is harmful’ approach to medicine neglects the dose response  relationship of drugs and other chemicals in the body. This hypothesis also ignores scientific research into
mechanisms of autism, the epidemiology of the increase in autism reports and the failure of the hypothesis to account for the continued rise of autism cases after Thimerosal was removed from the majority of vaccines.

The web-based resource Science Based Medicine has a reference page containing summaries of and links to the various studies showing no link between Thimerosal in vaccines and development of autism or autism spectrum disorder (ASD)5. The studies in aggregate looked at the claim of a link between Thimerosal and autism in a number of ways. Several looked at large groups of individuals and attempted to find any sort of correlation between childhood exposure to Thimerosal and development of autism symptoms. All together these studies combed through the data of over 750,000 individuals in several different countries and found no evidence to support a link.

Continuing to disseminate information that implies a link between Thimerosal and autism is to be either wilfully ignorant of the current state of research, in which case claims to educational content are not accurate, or to be dismissive of the current research as being an inaccurate reflection of the facts. This second option depends on there being some sort of conspiracy within the scientific/medical community to hide the truth. No such conspiracy can be substantiated.
As an side, the MMR vaccine has also been linked to development of autism in the minds of anti-vaccine campaigners since Andrew Wakefield’s now discredited and retracted paper in the Lancet6. A Cochrane review of the evidence shows

’No credible evidence of an involvement of MMR with either autism or Crohn’s disease was found.’


’Exposure to MMR was unlikely to be associated with Crohn’s disease, ulcerative colitis, autism or aseptic meningitis…’7


1. Thimerosal clarification of chemistry:
The chemical IUPAC name of Thimerosal is actually
Ethyl(2-mercaptobenzoato-(2-)-O,S)mercurate(1-) sodium.
This breaks down to Ethyl Mercury in the body.

2. Vaccine ingredients:
a. Childhood vaccine Schedule:

b. Influenza Vaccines:

3. MSDS cited on the IAS website:

4. Misleading video posted under the heading ’Thimerosal in your Vaccine?’:


5. The Science-Based Medicine resource page on Vaccines and Autism:

6. Andrew Wakefield:

7. Cochrane review:

Filed under: Medicine, Questionable Techniques, Sciblogs, Science, skepticism Tagged: anti-vaccine, antivax, Autism, IAS complaint, Science, Science and Society, Thimerosal, Vaccine, vaccine ingredients, Vaccines

0 Responses to “IAS Complaint Part 1: Thimerosal in Your Vaccine? No.”

  • The research into the autism link had to be done just in case something was overlooked or if there was a small chance of a problem. Public confidence has been affected quite badly by rumours and bad research by the likes of Wakefield and the IAS. Public confidence in vaccines is really important if it is to continue its successes.

    Now that the extra evidence has been gathered and added to what was already out there hopefully the money can now be diverted back into tracing the actual causes of ASDs.

  • That’s a very important point Simon, while money is being spent on the spurious lines of study the real stuff takes a hit.

  • I’m absolutely gob smacked, I thought the rules for registering as a charity were more rigorous than that. Especially the educational one.

    If you don’t mind me saying so, “insinuates that Ethyl Mercury (also known under the trade name Thimerosal)….” isn’t quite correct. Thimerosal is not Ethyl Mercury. It’s more correct to say that it’s a substance that was used as a preservative/anti-septic in vaccines with the formula C9H9HgNaO2S. It disassociates to release some Ethyl Mercury which is much less toxic and eliminated out of the body quite quickly. The risk assessments back in the 1990’s were based on Methyl Mercury (rather different in effect) so in the event, they were very conservative. One of the things anti-vaccine groups tend to do is paint with a broad brush, as you note with ignoring that the dosage needs to be taken into account. Therefore, you get Thimerosal becoming “mercury” instead of saying it’s a mercury containing compound. I think that is deliberate though, it’s scarier thinking of mercury.

    It’s also important to note it’s use in vaccines was valid – to prevent microbial contamination which could really cause harm and was a real risk, especially when accessing multi-dose vials.

    “The research into the autism link had to be done just in case something was overlooked or if there was a small chance of a problem.”

    I don’t have a problem with researchers, whilst investigating vaccine safety, deciding to look at associations with possible neurological effects. I do have a problem with having to spend hundreds of thousands of dollars of research money better spent elsewhere based on spurious claims by anti-vaccine groups and then, spending more as they move the goalposts and say, oh, but they only looked at one vaccine or one ingredient. In the meantime, in between the time the anti-vaccine groups are making theses claims and in the time it takes to research it they have a ton of time of spread misinformation. Not that they accept negative results anyway, I’m still seeing anti-vaccine people pushing long debunked claims about DPT vaccine, so this isn’t the only time it’s occurred. Even worse, there is a blatant financial motive for this – if the anti-vaccine groups can push through an unsupported claim they can access compensation that otherwise just isn’t available to them. That’s why Wakefield’s “research” was linked to lawyers working on a case involving MMR, that’s why they had the Autism Omnibus case in the US. Both failed, despite only having to reach the balance of probability to succeed. There was not, and still is not the evidence there to even make that link.

    The better way to deal with this is to shut them down at the start, unless there is something more than something they’ve pulled out of their nether regions. In this case, we knew way back when that Autism had a strong genetic component, and with other known causes (such as Rubella) exposure was during early pregnancy. In addition, mercury while it may be associated with neurological changes, none of it resembles anything like Autism. The first thing these groups should have got was not media coverage, but some very hard questioning about what the basis of the claim was and whether there was some hard evidence there of a problem before scientists and health professionals were put on the back foot trying to push back against a claim with pretty much no merit from the outset.

    It’s really more about sowing doubt, and in that anti-vaccine groups succeeded and won what was really a public relations war rather than a scientific argument and we are still seeing the effects now. That they can continue to push that claim despite all the evidence against it tells it’s own story.

  • Thanks for the comment Michelle,
    About Thimerosal, note footnote 1. I was informed about the exact chemistry of Thimerosal after this piece was written and quite lazily just added a footnote rather than alter the text.*

    Regarding financial motivations, I quite wary of ascribing these sort of motivations (though in Wakefields case it’s entirely appropriate). Perhaps I’m naive but I prefer to think of the majority of anti-vaxers are simply misguided rather than lead by base desires in that fashion. No doubt some are motivated in this way but over generalisations are what the “other side” engage in.

    I agree that the best thing would have been to get the anti-vax side to answer the hard questions at the start to show they actually had nothing but that I think requires a quite critically minded and scientifically literate public (one of the purposes of Sciblogs :)) as it is the publics imagination that is caught by these claims and carry them along.

    How can we foster the sort of attitude that would head these ridiculous claims “off at the pass”? I don’t really know.

    Best I can figure to do is, as you’ve probably noticed, try to play catch-up and debunk the claims after the fact.

    (* In my defence Thimerosal and Ethyl Mercury are used interchangeably in many circles so at least I’m covering two bases to get my point across. A poor excuse but…)

  • Michelle –

    Good comment.

    I think that is deliberate though, it’s scarier thinking of mercury.

    Mercury has long been in the media/public mind since the mercury poisoning in Japan, e.g. the so-called Minamata disease. (Terrible! I’m citing wikipedia!) I think the public eye of it follows from this; it was widely reported at the time, I believe.

    I do have a problem with having to spend hundreds of thousands of dollars of research money better spent elsewhere based on spurious claims by anti-vaccine groups and then, spending more as they move the goalposts

    I agree – I’ve written words to similar effect in some of my earlier autism articles. There’s a point that the thing has been shown and you have get back to the positive stuff.

    with other known causes (such as Rubella) exposure was during early pregnancy

    Must look this up. The one time I’ve looked in this general direction was via a note in one of Offit’s articles. From memory it proposed a link between prenatal rubella and schizophrenia in the children as they grew up. (Maybe it was with autism and I’m recalling incorrectly?) I looked at the paper and wasn’t really convinced. Anecdotally, it seems too small a study with no-obvious issues and no follow-up in many years. At least that’s my recollection! – someone who knows this area can correct me.

    I’m not so sure it’s about “sowing doubt’ so much as tilting at windmills – they seem to have a mix of ‘science’ (that you and I might read as ‘hopeful readings’, well-meant or otherwise) and what, if you strip this away, are essentially attacks on those they perceive as either ‘wrong’ or ‘telling them what to do’.

    [edited for quotes, DC]

  • On the “sowing doubt” issue, I think I agree with Michelle. Whether or not that’s the concious intention, the goal is to reduce trust in vaccines.

    Throwing up (mis)information that gives people a reason to distrust vaccines (mercury, foetal tissue, formaldehyde etc) achieves this goal.

  • Excuse the lack of quotes in my previous comment – it seems WordPress doesn’t honour bq tags in comments or whatever.

    Darcy: It’s probably a matter of who and interpretations? Different people will have different inner goals – ? There’s no doubt that they aim to spread distrust over vaccines, but I also see an element of ‘distrusting authority’, as it were, in the way that some of those that push anti-vaccine views approach it. I think there is more than just a ‘misreading’ of science to this. Just my current view. Which may even change tomorrow! 😉

    • added the correct tags, if you don’t mind. Looks like the tags for this are blockquote rather than bq. Wish there were buttons on the page for this, seems like everything has slightly different conventions.

      Which appears to still not be displaying properly, buggerit.

  • This is one of the big wins for the MMR vaccine. Congenital rubella was one of the leading causes of mental retardation until the vaccine was introduced. I don’t think it is classified as an Autistic Spectrum Disorder though.

  • > I thought the rules for registering as a charity were more rigorous than that. Especially the educational one.

    It depends on the wording of the rules submitted to the Commission at the time of application. The IAS have worded theirs very carefully to appear to be educational and serving a community service but their actions prove otherwise. They wouldn’t have been registered if they had been honest and included the following in their rules:

    * “To halt all vaccinations in this country”
    * “To increase the chances of disease”
    * “To actively spread misinformation to reach our goal”
    * “To lie when it suits us”
    * “To blatantly cherry pick research”
    * “To present non-scientific surveys and present them as valid studies”
    * “To embrace the return of diseases such as polio and smallpox”

    Here are their rules:

  • This is one of the big wins for the MMR vaccine. Congenital rubella was one of the leading causes of mental retardation until the vaccine was introduced. I don’t think it is classified as an Autistic Spectrum Disorder though.

    My thoughts too. Prenatal infection can cause “mental retardation”, that’s well-known, but I wasn’t under the impression that there was autism, etc. associated with it. Having said that, I’m not familiar with this literature. I chased up the one paper I mentioned quite a while ago (as in a good number of years ago now) and at the time I couldn’t find much else supporting it. Looking quickly it seems there are more papers out (since), which may (likely, have?) have made a sound case for it.

    If only I had endless time and I could read all the leads that are interesting!

  • Which appears to still not be displaying properly, buggerit.

    So, it’s back to italics! 🙂

    Wish there were buttons on the page for this, seems like everything has slightly different conventions.

    I’ve seen other forums offer a (cut-down) visual editor for comments. Very nice, but it’d cost the SMC to put it in place. Any wealthy sponsors out there?

  • Sorry, your claims about Thimerosal are ignorant at best or dishonest at worst. Read this document and see the abundance of evidence in the scientific literature attesting to the following statement of fact by Robert F. Kennedy:

    Tobacco Science and the Thimerosal Scandal, Robert F. Kennedy Jr.

    “Indeed, the link between ethyl mercury and neurological disorders is as well-documented in medical and scientific literature as the link between tobacco and cancer. And the totality of the evidence is overwhelming. Scores of animal, DNA, epidemiological, clinical, cadaver and other studies point to mercury as a prime culprit in America’s epidemic of neurological disorders. Toxicological studies show mercury, in all forms, is a potent neurotoxin, and many studies support a relationship between thimerosal exposure and neurodevelopmental disorders. Animal studies and experimental studies clearly document biological and molecular abnormalities in brains exposed to thimerosal.”