The World Health Organization’s Global Advisory Committee on Vaccine Safety (GACVS) has reaffirmed that there is no evidence of a causal relationship between vaccines and autism spectrum disorder (ASD) following a comprehensive review of scientific evidence published from January 2010 to August 2025.
The committee examined two recent systematic literature reviews addressing the potential link between vaccines — including those containing thiomersal — and ASD, and found that the majority of high‑quality studies did not support any association.
The evidence base included 31 primary research papers from 11 countries and five meta‑analyses; methodologically rigorous studies consistently showed no link between vaccines and autism, while studies suggesting an association were judged to have significant methodological limitations and high risk of bias.
A separate review of human studies on aluminium‑adjuvanted vaccines likewise found no association with chronic or systemic disorders, and a large cohort study from Denmark reinforced the absence of a connection between aluminium‑containing vaccines and ASD.
GACVS reaffirmed its previous conclusions from reviews conducted in 2002, 2004 and 2012 that the available high‑quality scientific evidence supports the positive safety profile of vaccines, including those used in childhood and pregnancy, and indicates that vaccines do not cause autism.
