inFact with Brian Dunning inFact with Brian Dunning


Vaccine Ingredients

Antivaccine activists claim that vaccines contain all sorts of terrifying poisons. Is this true?

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Antivax conspiracy theorists tell us that vaccines are deadly and contain some extraordinary toxins. Let's examine a few of these ingredients, starting with:

FORMALDEHYDE: Absolutely true. Formaldehyde is used to sterilize some vaccines. We use formaldehyde for this because it's found naturally in the human body, as it's a normal byproduct of metabolism and digestion.

ANTIFREEZE: False. However some vaccines are sterilized with something called 2-phenoxyethanol, which is also used as a topical antibacterial for wounds. This and antifreeze come from the same family of hydrocarbons, but they are not the same thing.

MERCURY: Sort of true. Some vaccines are sterilized with thimerosal, also used in contact lens fluid and many other products. However, it contains mercury bound as an ethyl -- the version of mercury that can be dangerous has to be bound as a methyl, which is different.

LATEX RUBBER: False. Latex is not in vaccines but it is in a lot of medical equipment, including gloves and syringes. Alternatives for most medical treatments are available to patients with latex sensitivities.

HYDROCHLORIC ACID: True. Hydrochloric acid is added to some vaccines to bring them to the same pH level as your body, just like it is with swimming pools, and just like your stomach naturally secretes hydrochloric acid to digest food.

ALUMINUM: True. Various forms of aluminum are used as an adjuvant, intended to increase the irritation to your body to provoke a stronger immune response. The amount contained in a vaccine dose is far less than what we consume environmentally every day.

ASPARTAME: False. Aspartame is not, and never has been, an ingredient in any vaccine. This one's just made up to scare you.

ABORTED FETAL TISSUE: Also false. But some vaccines do contain proteins that have to be grown in cultures of things as weird monkey or chicken kidney tissue, even chicken eggs. Some proteins are even extracted from human blood donations.

LIVE VIRUSES: True. Some viruses don't retain their chemical markers well enough when they're dead in order for the immune system to recognize them, so a very few vaccines are given with the viruses still alive, but weakened so they no longer pose a threat.

The list goes on and on. The ingredients in every vaccine are listed and are widely available, there's simply nothing there that anyone needs to hide. Got a question? Look up the ingredients. Everything there is there for a reason.

— Brian Dunning

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References & Further Reading

AAP. "Vaccine Ingredients." Immunization. American Academy of Pediatrics, 20 Jan. 2011. Web. 25 May. 2011. <>

CDC. "Ingredients of Vaccines - Fact Sheet." CDC. U. S. Federal Government, 19 May 2009. Web. 11 Feb. 2010. <>

Janeway, C., Travers, P., Walport, M., Shlomchik, M.J. Immunobiology. New York: Garland Publishing, 2001. 582-583.

Marshall, Gary. The Vaccine Handbook. West Islip: Professional Communications, Inc., 2008.

Ragupathi G., Yeung K., Leung P., Lee M., Lau C., Vickers A., Hood C., Deng G., Cheung N., Cassileth B., Livingston P. "Evaluation of widely consumed botanicals as immunological adjuvants." Vaccine. 2 Sep. 2008, 26(37): 4860-4865.

Ribeiro C., Schijns V. "Immunology of vaccine adjuvants." Methods Molecular Biology. 1 Jan. 2010, 626: 1-14.


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