Global Vaccine Safety

Aluminium adjuvants

Extract from report of GACVS meeting of 6-7 June 2012, published in the WHO Weekly Epidemiological Record on 27 July 2012

The GACVS reviewed 2 published papers alleging that aluminium in vaccines is associated with autism spectrum disorders3, 4 and the evidence generated from quantitative risk assessment by a US FDA pharmacokinetic model of aluminium-containing vaccines.

GACVS considers that these 2 studies3, 4 are seriously flawed. The core argument made in these studies is based on ecological comparisons of aluminium content in vaccines and rates of autism spectrum disorders in several countries. In general, ecological studies cannot be used to assert a causal association because they do not link exposure to outcome in individuals, and only make correlations of exposure and outcomes on population averages. Therefore their value is primarily for hypothesis generation. However, there are additional concerns with those studies that limit any potential value for hypothesis generation. These include: incorrect assumptions about known associations of aluminium with neurological disease, uncertainty of the accuracy of the autism spectrum disorder prevalence rates in different countries, and accuracy of vaccination schedules and resulting calculations of aluminium doses in different countries.

The GACVS also reviewed the US FDA risk assessment model of aluminium in vaccines. The FDA calculations incorporate the most recently published aluminium risk assessments by adjusting for gastrointestinal absorption and uptake from the site of injection. The FDA analysis indicates that the body burden of aluminium following injections of aluminium-containing vaccines never exceeds safe US regulatory thresholds based on orally ingested aluminium even for low birth-weight infants. GACVS concludes that this comprehensive risk assessment further supports the clinical trial and epidemiological evidence of the safety of aluminium in vaccines. Current research on pharmacokinetics of aluminium in vaccines is ongoing and should be encouraged as a means of further validating and improving this model.

3Tomljenovic L, Shaw CA. Do aluminum vaccine adjuvants contribute to the rising prevalence of autism? Journal of Inorganic Biochemistry, 2011; 105: 1489–1499.

4Tomljenovic L, Shaw CA. Aluminum vaccine adjuvants: are they safe? Current Medicinal Chemistry, 2011; 18(17):2630–2637.