A new analysis by a World Health Organisation global expert committee has found that there is no causal link between vaccines and autism spectrum disorders, reaffirming the WHO’s long-standing position that childhood immunisation does not cause autism.

The findings were reached by the Global Advisory Committee on Vaccine Safety, an independent body established in 1999 to provide authoritative scientific advice to the WHO on vaccine safety priorities worldwide. The committee said its latest review, discussed at a meeting held on November 27, 2025, examined the relationship between vaccines and autism using the most recent and robust evidence available.

According to the committee, the analysis focused on two key areas: thiomersal-containing vaccines and vaccines in general in relation to autism spectrum disorders. The review drew on evidence from 31 primary research studies published between January 2010 and August 2025, covering data from multiple countries. The committee reported that the findings strongly support the safety profile of vaccines used during childhood and pregnancy and confirm the absence of any causal association with autism.

The committee also evaluated potential health risks linked to vaccines that contain aluminium adjuvants. This assessment was based on studies conducted between 1999 and March 2023, as well as a large cohort study that analysed nationwide registry data of children born in Denmark between 1997 and 2018. In its summary, the committee said the available high-quality evidence shows no association between the trace amounts of aluminium used in some vaccines and autism spectrum disorders, supporting the continued use of vaccines with aluminium adjuvants.