Aluminum, mercury in vaccines shown safe and effective in multiple studies | Fact check

The claim: The safety of aluminum and mercury in vaccines has never been studied

A Feb. 20 Instagram post (direct link, archive link) raises doubts about the safety of two metals found in some vaccines.

“Show me any studies that prove that the heavy metal preservatives in vaccines – mercury and aluminum – have been proven safe for infants, children or adults?" the post reads. "There are none, those studies have never been done.”

The post was liked nearly 200 times in two days.

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Our rating: False

This is nonsense. Both metals have been studied extensively and determined to be safe and effective as used in vaccines. The post also mischaracterizes aluminum by calling it a preservative.

Decades of research support safety claims

Misinformation about the safety of mercury in vaccines typically centers on concerns of a possible link to autism, something that has been debunked repeatedly. USA TODAY has previously reported that thimerosal, the mercury-containing preservative found in multi-dose vials of some vaccines, was removed from use in most vaccines despite a lack of evidence connecting it to an increase in autism cases.

The form of mercury in thimerosal, ethylmercury, is easily filtered out by the body and is not linked to any health issues. A 2010 review of literature found it filtered out significantly faster than the more concerning methylmercury, which is not used in vaccines.

The research supporting the safety of the form and amount of mercury in vaccines includes a 2010 study by the Centers for Disease Control and Prevention that found "exposure to ethylmercury from thimerosal-containing immunizations during pregnancy or as a young child, was not associated with any of the (autism spectrum disorder) outcomes."

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Similarly, multiple studies have established the safety of aluminum in vaccines.

A 2019 review published by the American Academy of Pediatrics found that claims of an autoimmune disorder linked to the aluminum in vaccines were unsubstantiated. The research found there were too many differences in the reported cases to link them to a common cause.

The post also mischaracterizes aluminum by calling it a preservative. Aluminum is used as an adjuvant, added to the vaccine to help stimulate a stronger immune response. Adjuvants in turn reduce the need for larger doses or multiple boosters.

A 2011 paper showed that infants following the recommended vaccination schedule have “significantly less” aluminum exposure than limits deemed safe by the CDC. A 2015 paper endorsed identifying and developing new adjuvants beyond aluminum salts, while still recognizing they have been demonstrated safe. And a 2018 paper showed that aluminum levels in children’s hair, a measure of how much is in the body, are not affected by whether they are vaccinated.

USA TODAY could not reach the social media user who shared the claim for comment.

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This article originally appeared on USA TODAY: Mercury, aluminum in vaccines are well studied | Fact check