Studies Supporting Aluminum Salts

Several scientific studies have evaluated the safety of aluminum in childhood vaccines, generally concluding that the amounts used as adjuvants do not pose significant health risks to children.

Danish Study. A nationwide cohort study in Denmark, published in 2025 in the Annals of Internal Medicine, analyzed more than 1.2 million children between 1997 and 2020. It found no associations between cumulative exposure to aluminum from vaccines and 50 chronic disorders, including autism, asthma, autoimmune diseases, or neurodevelopmental disorders, even in dose-dependent analyses.

Meta-analyses and Previous Reviews. Jefferson et al. (2004) conducted a meta-analysis of five studies comparing vaccines with aluminum hydroxide versus those without adjuvants in children under 18 months of age, finding only minor local effects such as redness, with no evidence of serious or lasting disorders. Additional studies confirm that aluminum in vaccines does not increase the risk of autism spectrum disorder (ASD).

Signals and follow-up studies. A 2023 observational study suggested a possible association between vaccine aluminum and persistent asthma in children with eczema, but it did not demonstrate causality and was limited by not considering environmental or dietary exposures. Subsequent research, such as the Danish study, has not confirmed this signal and reinforces the overall safety.

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