A new analysis from the World Health Organization (WHO) has reaffirmed that there is no causal link between vaccines and autism spectrum disorders (ASD). The findings, presented by the Global Advisory Committee on Vaccine Safety (GACVS) on November 27, 2025, reinforce the WHO’s long-standing position that childhood vaccines do not contribute to autism.
The GACVS, established in 1999, comprises international experts who provide independent scientific guidance to the WHO on vaccine safety. In its latest review, the Committee examined a range of studies focusing on thiomersal-containing vaccines and their potential association with ASD, along with a broader assessment of vaccines in general.
The analysis drew upon evidence from 31 primary research studies published between January 2010 and August 2025, incorporating data from various countries. The findings consistently demonstrated a strong safety profile for vaccines administered during childhood and pregnancy, confirming the absence of a causal link to ASD.
Thiomersal and Aluminum Adjuvants
The Committee also evaluated potential health risks linked to vaccines containing aluminum adjuvants, referencing studies conducted from 1999 through March 2023. Additionally, it reviewed a significant cohort study analyzing nationwide registry data of children born in Denmark between 1997 and 2018. The comprehensive review indicated no association between the trace amounts of aluminum present in certain vaccines and the occurrence of ASD. This supports the continued use of vaccines that contain aluminum adjuvants.
After reviewing the available data, GACVS reaffirmed its previous conclusions from 2002, 2004, and 2012, stating firmly that vaccines, regardless of whether they contain thiomersal or aluminum, do not cause autism.
Encouragement for Vaccine Policy
In light of these findings, the WHO urges national health authorities to base their vaccine policies on the latest scientific evidence. Global childhood immunization initiatives have been pivotal in enhancing public health, saving at least 154 million lives over the past 50 years. The WHO continues to advocate for comprehensive vaccination programs, emphasizing their role in improving health outcomes, livelihoods, and societal prosperity.
The latest analysis serves as a vital reminder of the importance of vaccination in public health, encouraging continued trust in vaccines as a critical tool for preventing disease and safeguarding future generations.
