Oct 21 2011

Fear Mongering the Flu Vaccine

In a recent article in The Canadian, journalist Anthony Gucciardi trots out long discredited anti-vaccine canards in the guise of actual journalism. The piece is poorly researched and resourced, blatantly biased, and amounts to little more than irresponsible fear-mongering about the flu vaccine.

Gucciardi writes:

Each dose of flu vaccine contains around 25 micrograms of thimerosal, over 250 times the Environmental Protection Agency’s safety limit of exposure.

Mercury, a neurotoxin, is especially damaging to undeveloped brains. Considering that 25 micrograms of mercury is considered unsafe by the EPA for any human under 550 pounds, the devastating health effects of mercury on a developing fetus are truly concerning.

Everything Gucciardi wrote is either outright factually wrong, or incomplete in a way that makes it highly misleading.

First – some forms of the flu vaccine (the multi-dose vials) do contain thimerosal, with 25 mcg of ethylmercury. But there are also many flu vaccines that contain no thimerosal and no mercury, because they come in single-dose vials and don’t require the preservative. Here is a list of all of the approved flu vaccines – you can see that eight of the vaccines listed have zero mercury, one is listed as having <= 1 mcg, and four are listed as having about 25 mcg.

I can see no reason why Gucciardi would have missed this fact – it’s almost as if he wants to scare his readers away from vaccines in general.

What about for those flu vaccines that do contain 25 mcg of mercury? Does this really exceed the EPA limit for safety? In a word, no, but this canard has been popular among anti-vaccine activists for years who, very much like creationists, would never abandon a useful argument simply because it’s factually incorrect.

First, the EPA limit is for methymercury, not ethylmercury, which is the form found in Thimerosal. Methylmercury is known to be much more toxic than ethylmercury. In addition ethylmercury (half life about a week) is cleared from the body much more quickly than methylmercury (half life about 1.5 months). Further, infants excrete mercury more efficiently than adults. The EPA safety limits are based upon the more toxic form of mercury, with a 10 fold built in safety buffer in case some people are more susceptible to mercury toxicity than others.

But even worse, Gucciardi completely misrepresents that nature of the EPA limits (the reference dose, or RfD, for methymercury is 0.1 mcg/kg). They are based upon safe daily consumption for life (the EPA uses 75 years as life-long consumption).

So Gucciardi confuses the EPA limit for daily lifelong consumption with one time or annual exposure. This is a pretty basic error, and it has been pointed out numerous times easily found on the internet.  Not content with the errors he has made so far, Gucciardi takes it up a notch:

The EPA’s safety limit of mercury exposure is being exceeded by over 250 times each shot. In addition to a number of other ‘recommended’ vaccines, flu shots are dished out each year to the public, meaning that this exposure increases to 250 times the limit each year. Over a 10 year period, it is possible to exceed the limit by 2500 times simply by receiving a yearly flu shot.

There is no doubt that Gucciardi is interpreting the daily limits as if they were a lifetime limit. It is not surprising, however, as he cites only secondary anti-vaccine sources, and not primary sources, for his information. He is, in essence, regurgitating anti-vaccine propaganda as if it were journalism.

Gucciardi bills himself as an “accomplished investigative journalist” but he has demonstrated here a combination of gross incompetence and extreme bias. In fact, he is a “natural medicine” advocate who has an anti-establishment medicine agenda. In other words, he is an activist masquerading as a journalist.

For good measure Gucciardi throws in some more anti-vaccine propaganda. To show how toxic mercury is he cites studies where workers exposed frequently to elemental mercury vapor developed toxicity. This has no relevancy, however, to thimerosal exposure. No one denies that mercury in high enough dose is toxic. But different forms and different doses have different toxic potential. Gucciardi chose studies that are as different from thimerosal as possible – acute exposure to inhaled elemental mercury vapor over a long period of time by workers. This tells us nothing about the effects of ethylmercury in some flu shots – but it can be used to scare the public.

Gucciardi also ignores the copious epidemiological evidence that shows a lack of correlation between thimerosal exposure and any adverse outcome, including autism. This evidence includes the fact that after thimerosal was removed from the routine childhood vaccine schedule in the US (complete by the end of 2002) there has been no change in the rate of increase of autism. Advocates of the thimerosal-autism hypothesis predicted that autism incidence would plummet. It didn’t.

He goes on to make what Orac frequently calls “the toxin gambit” by listing listing the “scary toxins” found in many vaccines. But the issue is the same – what’s the dose, and what is the evidence for safety?   For example, he mentions formaldehyde without mentioning the fact that the amount found in vaccines is less than the amount formed naturally in the body as a consequence of normal metabolism.

He writes: “Triton X-100: A detergent that should not be injected into the human bloodstream.” Well – vaccines are not injected into the bloodstream. They are given either intramuscularly or subcutaneously – never intravenously. That aside, again we are left with the real question – is it safe at the doses given? This, of course, has been studied and Triton X-100 has been found to be safe in those flu vaccines in which it is used.

Gucciardi then takes a swipe at another anti-vaccine claim – that the young immune system cannot handle the stress of vaccines and this can lead to, among other things, autoimmune disease. He gives a single reference to this – an article by one crank (in my opinion), Russel Blaylock, posted on the website of another crank, Mercola. Again we see that Gucciardi relies exclusively on secondary anti-vaccine sources (violating basic rules of journalism and scholarship).

The information he is citing has to do with the HepB vaccine, not the flu vaccine (and so is of dubious significance to the issue at hand, unless your goal is to fear-monger about vaccines in general). He writes:

In essence, they found that the babies responded to the vaccine by having an intense Th2 response that persisted long after it should have disappeared, a completely abnormal response.

This is a complex topic and I cannot do it justice in this post. But quickly – this issue has been and is being researched. One thing we have learned about the immune system is that it is damn complex, and we cannot extrapolate from simple basic science findings to net clinical outcomes. So citing one paper about differences in immune response between children and adults is not enough to make any conclusions. Further, his characterization of the response of children in this study as “a completely abnormal response” is nonsensical and not based on any science.

The massive cherry picking that Gucciardi is engaged in is also evident. Other studies, for example show that children who received the HepB vaccine had no increase in autoantibodies years later. There is, in short, no evidence that giving young children vaccines signifciantly increases their risk of developing autoimmune diseases. Rare cases of vaccine-induced autoimmunity are possible and reported, but you can also get autoimmunity from getting the diseases that the vaccines prevent.

As with everything in medicine, you need to take a risk vs benefit approach. Vaccines have risks, but they are generally low, while the benefits are large and clear.


At every step Gucciardi mindlessly repeats long-discredited anti-vaccine canards, cites anti-vaccine sources as authoritative, cherry picks evidence, and grossly misrepresents the facts.

The EPA limit for mercury claims is especially egregious, and so easily and demonstrably false.

But, flu season is on the way, and now is the time to get  your flu vaccine if you want to be protected. It is therefore also the time for the anti-vaccine movement to trot out their tired arguments, doing their best to hamper effective public health interventions with fear-mongering.

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