A recent analysis by the World Health Organization (WHO) has reaffirmed the absence of any causal link between vaccines and autism spectrum disorders (ASD). The finding, announced on December 12, 2025, was made by WHO’s Global Advisory Committee on Vaccine Safety (GACVS), which analyzed the latest scientific data to provide independent advice on global vaccine safety.
The GACVS, established in 1999, reviewed the evidence from 31 primary research studies published between 2010 and 2025, which included data from multiple countries. The findings strongly support the safety of childhood and pregnancy vaccines and confirm there is no causal relationship between vaccines and ASD.
The Committee also focused on the safety of vaccines containing thiomersal (a mercury-containing preservative) and aluminum adjuvants. Evidence from the studies, conducted from 1999 to 2023, shows no association between these components and autism. This includes data from a significant cohort study of children born in Denmark between 1997 and 2018, which further supports the safety of vaccines.
WHO reiterated its position that autism spectrum disorders, which are characterized by social and communication difficulties, and atypical patterns of behavior, are not caused by vaccines. The analysis of autism also emphasized that while the condition can be detected early, it is often diagnosed much later, with varying levels of intellectual functioning among individuals with ASD.
These findings highlight the ongoing safety of vaccines and reinforce WHO’s commitment to supporting the use of vaccines in public health worldwide.
