No evidence that aluminum in vaccines is unsafe or causes autism | Fact check

The claim: Aluminum, mercury in vaccines cause autism; aluminum exceeds safe limit

A Dec. 31, 2023, Instagram post (direct link, archive link) shows a video of a woman crossing out the word "don't" in the phrase "vaccines don't cause autism" so the message reads "vaccines cause autism."

In support of this claim, the post's caption makes a calculation based on a package insert listing the possible amount of aluminum in a hepatitis B vaccine and the average weight of a newborn.

Based on this calculation, the user concludes that newborns given the hepatitis B vaccine are exposed to an amount of aluminum "28 TIMES HIGHER what they have told us is the safe limit (sic)."

The caption also claims children are exposed to mercury through vaccines and that "exposure to mercury can give rise to the traits defining or commonly found in individuals with (austism spectrum disorder)."

The post was liked more than 3,000 times in three weeks.

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Our rating: False

Multiple studies have shown the aluminum in infant vaccines is safe and not linked to autism. The social media user’s attempted calculation of aluminum exposure limits uses a draft guideline for IV nutrition for infants that isn't related to vaccines. And the post’s claim about mercury in vaccines contributing to autism has been repeatedly debunked.

Post compares aluminum levels from two different applications

The post's claim of unsafe levels of aluminum in vaccines is based on draft FDA guidelines for acceptable levels of aluminum in parenteral nutrition, which is provided intravenously for infants. That standard is irrelevant to assessing safe aluminum exposure from vaccines, experts told USA TODAY. Vaccines continue to be recognized as safe and unrelated to autism.

“The aluminum in vaccines is in a form that's been proven safe and effective for triggering the immune response we want,” Dr. Taison Bell, a UVA Health specialist in infectious diseases and critical care medicine, wrote in an email.

He said the draft guidelines for aluminum exposure limits in IV nutrition are different than those used for vaccines, a difference that reflects the different purposes, methods of administration and absorption of the two products.

Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia, said the amount of aluminum infants receive from vaccines is a fraction of what they receive from nursing or formula.

The American Academy of Pediatrics says the use of intravenous solutions containing aluminum, such as parenteral nutrition, should be monitored. They could carry a greater risk of aluminum toxicity because they don’t pass through the gastrointestinal mucosa, which helps prevent aluminum absorption by the body.

The December 2022 draft guidelines cited in the post recommend limits on aluminum exposure through parenteral nutrition based on an infant’s weight and days of life, which the post accurately reflects as 17.5 micrograms for a 1-day-old baby weighing 3.5 kilograms.

However, the limit of aluminum in vaccines is 1.25 milligrams per dose, with the further requirement that the amount in a vaccine is no more than can be shown with data to be needed to cause the desired immune response without health impacts. Aluminum salts are used as adjuvants, which stimulate a stronger immune response.

There is a large body of research supporting the safety of the way aluminum is used in vaccines. A 2011 paper showed that infants following the recommended vaccination schedule have “significantly less" aluminum exposure than limits deemed safe by the Centers for Disease Control and Prevention. 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.

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The post also revisits the oft-debunked claim that mercury in vaccines causes autism. Multiple studies show no link between autism and the mercury in vaccines, said Cherie Duvall-Jones, an FDA spokesperson. In fact, the post accurately notes that mercury is no longer found in routine childhood immunizations.

When mercury is present in vaccines, it is found in thimerosal, a preservative used in multi-dose vials to prevent bacteria and fungi growth. Vaccine manufacturers and other groups agreed in 1999 to reduce or eliminate its use out of an abundance of caution.

USA TODAY previously reported that the form of mercury in thimerosal, ethylmercury, is easily filtered out by the body and is not linked to any health issues. Methylmercury, another form, can accumulate.

USA TODAY reached out to the social media user who shared the claim for comment but did not immediately receive a response.

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This article originally appeared on USA TODAY: Aluminum, mercury in vaccines not linked to autism | Fact check