Aluminum in vaccines poses no danger

Aluminum has long been used as an adjuvant in a number of vaccines, including those against diphtheria, tetanus, pertussis, hepatitis A and B, Hib infection, and pneumococcus. The metal’s ability to enhance the immune response makes it an indispensable component in inactivated vaccines. However, there has been growing concern recently about the potential role of aluminum in the development of autoimmune and allergic disorders and neuropsychiatric pathologies. In response to these concerns, a recent study conducted in Denmark and published in the Annals of Internal Medicine provided strong evidence that no such link exists.

The study covered more than 1.2 million children born in Denmark between 1997 and 2018. Using data from national medical registries, the authors analyzed information on vaccinations in the first two years of life—the period when children receive the most aluminum-adjuvanted vaccines. A unique feature of this analysis is that children born in different years received different combinations of vaccines, which led to natural variation in the cumulative dose of aluminum—from 0 to 4.5 mg. This study design limited the influence of bias and confounding factors.

The aim was to assess whether there is a link between the amount of aluminum administered and the risk of developing 50 chronic diseases, in particular autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), autoimmune diseases (endocrine, hematological, and rheumatological), and atopic conditions (asthma, atopic dermatitis, allergic rhinitis).

The results showed that there was no increase in the risk of developing autoimmune diseases with higher aluminum accumulation. Moreover, the dose of aluminum did not correlate with a higher incidence of allergic disorders, even common ones such as asthma or eczema. As for neuropsychiatric disorders, there was even an unexpected slight inverse association: a 1 mg increase in cumulative aluminum dose was associated with a 7% reduction in the risk of ASD and a 10% reduction in the risk of ADHD.

The results of the Danish study contradict the data from previous small cohort studies, which indicated a weak link between aluminum in vaccines and an increased risk of atopic diseases. However, these scientific studies did not take into account the influence of factors such as smoking during pregnancy and genetic predisposition to allergies. The new analysis used a wide range of adjusting variables: socioeconomic status, parental diseases, number of children in the family, and others. The results once again confirm the advisability of continuing to use aluminum-containing vaccines in national immunization programs.