Thimerosal: Why We Need To Open the Debate on Safety

Disclaimer: As a Functional Medicine doctor, it is my intent to seek out and present many approaches to health and recommend what is best for my patients on an individual basis. In the case of vaccines, I am pro-vaccine-safety; I believe they can be helpful and necessary but that we should continue to pursue a more nuanced scientific perspective about the risks versus benefits in uniquely susceptible populations.

Vaccinations are among the most important advances in medicine in the last century. We have eradicated smallpox from the planet and dramatically reduced death and suffering from infectious disease around the globe. I am aggressively pro-vaccine. I am a father and family physician. I have vaccinated my children. I have been vaccinated and recommend vaccination to my patients. Critics of Thimerosal: Let the Science Speak, edited by Robert F. Kennedy, Jr., will quickly polarize the debate. It is easy to oversimplify the issue of thimerosal into pro-vaccine or anti-vaccine, into pro-science or anti-science, or to attack his character rather than discuss the actual science. The history of medicine is replete with personal attacks that subvert open debate. Critics will confuse this issue by debating whether thimerosal causes autism, which has not been definitively proven and is not the subject of the book or the issues raised about thimerosal. This is unfortunate, and detracts from a much simpler set of questions that are ultimately the subject of this scientifically dense book. Anyone who feels this issue is closed should take the time to carefully review the book and the hundreds of scientific references on which it is based. There is no debate that mercury in any form is toxic. Scientists may debate the differences in toxicity between different forms of mercury such as ethylmercury (thimerosal) or methylmercury (from fish). But all would agree that mercury is a potent neurotoxin. It is unfortunate that TIME magazine reported without adequate fact checking that "The quantity of ethylmercury that was once in vaccines was so small that it was actually within acceptable limits for the more toxic, methyl form--but it wasn't even in that methyl form to begin with." This PowerPoint from the Institute of Medicine shows that the two forms of mercury are only slightly different. It concludes: "Ethylmercury should be considered equipotent to methylmercury as a developmental neurotoxin." If the toxicity of methyl and ethyl mercury should be considered equivalent, and the EPA’s (Environmental Protection Agency) maximum acceptable reference dose (RfD) for methylmercury were applied to thimerosal (ethylmercury), then a child given a single dose of thimerosal-preserved flu vaccine which contains 25 micrograms of mercury would have to weigh 250 kilograms (or 550 pounds) to be considered safe. There is also no debate about the dramatically increased prevalence of neurodevelopmental disorders over the last few decades, including learning disabilities, attention deficit disorders, and autism. There may, however, be debate on the strength of the data and science implicating mercury in this increased prevalence of brain injury in children. These questions can never be adequately answered given the challenges of doing experimental studies on human subjects over long periods of time. Obviously, no ethical review board would ever approve a study in which children were purposefully exposed to mercury in order to test its toxicity. Population studies show correlations, but never prove causation, making it impossible to draw firm conclusions. That leaves us with a very simple, moral question, and ultimately a very personal one. Because at some point in our lives, nearly all of us will have a child or grandchild who requires vaccinations. Or we will know a pregnant woman who will have to decide whether or not to get a flu shot that might contain mercury. All of us are people and parents first, and scientists and policymakers second. So there is only one question that really matters.

Would you expose the unborn child or infant of a loved one to a vaccine containing mercury, a known neurotoxin, if there were other safer alternatives?

The answer to this question is simply common sense and requires no further scientific inquiry, but as Voltaire said, “common sense is not so common.” If there were no other options, if it were a question of whether to vaccinate or not to vaccinate, then, of course, we would choose vaccination. But that is a false choice. There are 137 million children born each year in the world. Is our only option to subject them to a potent neurotoxin in their most delicate neurodevelopmental period? How can we best protect that future generation from preventable harm? The arguments put forth that we cannot remove thimerosal from vaccines are invalid. Thimerosal has already been removed from nearly all vaccines except the multi-dose flu vaccine in the United States. This was based on government recommendations and a call to action from many agencies and health organizations as well-documented the book. However, thimerosal still remains in nearly all the pediatric vaccines used in the developing world. There are effective alternative preservatives already in use (2-phenoxyethanol) and new ones can be developed. The Food and Drug Administration (FDA) banned mercury as a topical antiseptic (remember Mercurochrome). And any medical products containing thimerosal or mercury cannot be thrown in the garbage. The Environmental Protection Agency (EPA) considers them hazardous waste. Does it make any sense that even though thimerosal is not safe to put on your skin, or to throw in the garbage, that it is safe to inject into pregnant women and babies? Cost considerations are also used as an argument to keep thimerosal in vaccines. There is a small cost increase to use single dose flu vaccines, but it is minor compared to the cost of neurodevelopmental disease in children. The global cost of taking thimerosal out of all vaccines is $300 million a year. In the developing world, studies show that there is significant wastage of multi-dose vials, making single dose vials comparable in cost. There are other arguments. Some scientists we spoke to at Health and Human Services said that thimerosal might contribute to the effectiveness of the vaccines. Any agent that increases vaccine effectiveness is referred to as an adjuvant. However, thimerosal is approved for use only as a preservative, not as an active ingredient and such use is illegal. What perplexes me is that few of the journalists writing about this issue recently have actually read the book or reviewed the science personally but rather accepted institutional pronouncements of safety. Science progresses by debate, not denouncements. And the science should never be closed on any subject – the nature of science is to constantly question hypotheses. To say the issue on thimerosal is closed is simply unscientific. Just as we now are learning that fat may not be the driver of heart disease and obesity, overturning decades of scientific pronouncements and government policies, we need to be open to a scientific debate on thimerosal. The FDA has now ruled that trans fats are not safe, but still allows injectable mercury in some vaccines. I think there is no place for mercury in any form in medical products, especially those injected into children and pregnant women. The precautionary principle suggests we should be better safe than sorry. The absence of evidence is not the evidence of absence. But in this case, there is abundant evidence if any journalist or scientist would take the time to read it as we did and is extensively documented in this book. While the strength of all the evidence is not equal, and the conclusions not completely definitive, the overwhelming weight of the data suggests that there is potential for great harm. I have been involved in reviewing and contributing ideas and scientific references to Thimerosal: Let the Science Speak. There were more than 1400 references in the original manuscript and I have reviewed most of them. The manuscript is a dispassionate and dense review of the actual literature and the history of thimerosal. For more insight, you can read the Executive Summary. I have also been involved in efforts to change regulatory and legislative policy to reduce potential harm from thimerosal. I do not belong to any organization connected in any way with this issue. Nor do I have any personal or financial interest in this issue other than a scientific and moral one. And as a physician, my Hippocratic oath is to “First, do no harm.” We should practice the precautionary principle in medicine and avoid doing harm whenever possible. And given the simple fact that mercury is toxic, I can come to no other conclusion than this: We should immediately remove thimerosal from vaccines and all other products used in medicine.
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