Question: “I heard there are toxins like mercury in vaccines. Is that true?”
Dr. LaSalle: First, let’s look at the word “toxins”. A toxin is anything that, in great enough quantity, can be harmful to the body. And, really, anything can be toxic. Water can be toxic to your body if you drink too much. Too much water can dilute out your electrolytes, like sodium and potassium, and can cause weakness, confusion, and even deadly heart rhythm problems. So, keep in mind that it is not the substance itself but the amount of the substance that really matters.
An organization called the Agency for Toxic Substances and Disease Registry (ATSDR) monitors for toxic levels of substances in medical products, like vaccines. They use a measure called the Minimum Risk Level to identify concerning levels of a substance. When the amount of a substance is below the Minimum Risk Level, it is deemed to have no toxic risk and is safe for use. NONE of the substances used in production of vaccines are above the MRL.
With regard to mercury, first we should recognize that, since 2001 (for nearly 20 years), there has been NO mercury in any US licensed vaccine other than the multi-dose influenza vaccine.
ETHYL mercury, in the form of Thimerosal, was previously used as a preservative in vaccines, to prevent fungal and bacterial contamination of multi-dose vials. This was important and necessary since fungal or bacterial contamination of vaccine, if then administered to patients, could cause serious harm.
METHYL mercury is the form of mercury that can accumulate in our bodies and be toxic to our nervous systems. We are more commonly exposed to this through consumption of certain fishes. But this is NOT what was used in vaccines. Vaccines contained ETHYL mercury, a form of mercury that is cleared much more rapidly from our bodies, is less likely to accumulate, and so is much less toxic.
Why was it removed from vaccines if it wasn’t worrisome to begin with? That is a very good question! It was removed to take it off the table as a concern, not because there was any evidence that it caused harm. Many argue that this only lent an air of believability to the “Thimerosal is toxic” claim and served to increase the cost of vaccines, now that each vaccine has to be individually packaged.
What is the take home message? There is no mercury in the majority of our vaccines and, even when there was, it was NOT TOXIC.