A new analysis by the World Health Organization’s (WHO) Global Advisory Committee on Vaccine Safety (GACVS) has confirmed that there is no causal link between vaccines and autism spectrum disorders (ASD). This conclusion reinforces WHO’s longstanding position that childhood vaccines, including those given during pregnancy, do not cause autism.
Established in 1999, GACVS brings together international experts to provide independent, authoritative scientific guidance on global vaccine safety priorities. The Committee’s latest review, discussed on 27 November 2025, examined the relationship between thiomersal-containing vaccines and ASD, as well as the broader association between vaccines and autism. Drawing on 31 primary research studies published between January 2010 and August 2025 across multiple countries, the evidence strongly supports the positive safety profile of vaccines and confirms the absence of a causal link with ASD.
The Committee also evaluated potential health risks associated with vaccines containing aluminum adjuvants, reviewing studies from 1999 through March 2023, including a large Danish cohort study of children born between 1997 and 2018. The high-quality evidence shows no association between the trace amounts of aluminum used in vaccines and ASD, supporting the continued use of aluminum-adjuvanted vaccines.
GACVS reaffirmed its previous conclusions from 2002, 2004, and 2012 that vaccines, including those with thiomersal and aluminum, do not cause autism. WHO advises national authorities to base vaccine policies on the latest scientific evidence. Global childhood immunization has been one of the greatest public health achievements, saving at least 154 million lives over the past 50 years and significantly improving the health, livelihoods, and prosperity of societies worldwide.
