The Vocabulary of Vaccines

            I pride myself on being very knowledgeable about vaccines. I know all the common arguments against vaccination and I’m generally aware of why they’re wrong. Yet it wasn’t until beginning to read Eula Biss’s On Immunity: An Inoculation that I realized I was pretty clueless about some of the fundamental aspects of what a vaccine actually is. Sure, I’ve heard of thimerosal and its infamy as “the mercury in vaccines,” but until recently I didn’t actually know what thimerosal was or what it does in our body. And I’d never even heard of squalene.

            Thimerosal is what is known as an organomercurial compound, which essentially means it is an organic (carbon-containing) molecule that contains one or more mercury atoms. It has antimicrobial properties, which “help prevent potentially life threatening contamination with harmful microbes” in multi-dose vaccines (FDA). In simpler terms, thimerosal kills any “germs” that may be lurking in vials of vaccine. Without it, these “germs” could be injected directly into our body and cause a far worse infection than the flu ever could.

            Our fear of thimerosal stems from the frightening connotations of a mercury-containing product being injected into our children’s bodies. However, not all mercury-based products are created the same. The FDA’s factsheet on thimerosal notes that this compound degrades to ethylmercury in our bodies, which “should be distinguished from methylmercury…[which is] the type of mercury found in certain kinds of fish” and “can be toxic to people” at high levels (FDA). Thimerosal exists as 0.001% to 0.01% of a dose of vaccine, which is “roughly the same amount of elemental mercury contained in a 3 ounce can of tuna fish” (FDA). The research (strongly) suggests that we’re not all going to die from the thimerosal in vaccines. And even if it were a concern, thimerosal “was removed from every childhood vaccine except multi-dose flu vaccines by 2002” (Biss, 11).

            Squalene is a naturally-occurring compound found in “a great many living things including the human body, where it is manufactured in the liver” (Biss, 10). In the vaccine world, squalene comes from various fish oils, including shark oil, and is used to “enhance the immune response when added to antigens” (WHO, 2006). Squalene is not currently used in vaccines in the United States, but retains its bad reputation due to a suggested link “between the health problems of Gulf-War veterans and possible presence of squalene in vaccines;” however, “squalene was not added to the vaccines administered to these veterans, nor was it used in the manufacturing process” and “various papers have [since] been published outlining the technical deficiencies in that original report” (WHO, 2006). Like thimerosal, squalene is essentially a non-issue for our health and safety.

            It is evident that many of the things we think we know about the “dangers” of vaccines have been scientifically debunked or are simply not true. Yet some of us would rather leave our children unvaccinated and at the mercy of nature than “risk” vaccinating them. And yet, science has told us time and time again that “if there [is] a problem with vaccines it [is] not with thimerosal, and it [is] not with squalene” (Biss, 11).

Biss, E. (2015). On immunity: An inoculation. Minneapolis, MN: Graywolf.

Center for Biologics Evaluation and Research. (n.d.). Vaccine safety & availability - Thimerosal and vaccines. Retrieved February 13, 2018, from https://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/VaccineSafety/UCM096228

World Health Organization. (2006, July 14). Safety of squalene. Retrieved February 12, 2018, from http://www.who.int/vaccine_safety/committee/topics/adjuvants/squalene/Jun_2006/en/

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