No link between vaccines and autism spectrum disorders

It added that the Committee also assessed the review of potential health risks associated with vaccines having aluminum adjuvants, drawing on studies conducted from 1999 to March 2023

2025-12-13

A new analysis by a World Health Organisation (WHO) global expert committee on vaccine safety has found no evidence of any causal link between vaccines and autism spectrum disorders (ASD). The conclusion reaffirms WHO’s position that childhood vaccines do not cause autism, the organisation said in a release on Friday (December 12, 2025).

The Global Advisory Committee on Vaccine Safety (GACVS), established in 1999, brings together international experts to provide independent and authoritative scientific advice to WHO on global vaccine safety-related priorities.

WHO explained that autism spectrum disorders are a diverse group of conditions characterized by some degree of difficulty with social interaction and communication. Other characteristics are atypical patterns of activities and behaviours, such as difficulty with transition from one activity to another, a focus on details and unusual reactions to sensations.

Characteristics of autism may be detected in early childhood, but autism is often not diagnosed until much later. People with autism often have co-occurring conditions, including epilepsy, depression, anxiety and attention deficit hyperactivity disorder. The level of intellectual functioning among autistic people varies widely, extending from profound impairment to superior levels.

Meanwhile, the latest analysis, discussed by the Committee on 27 November, focused first on the relationship between thiomersal-containing vaccines and ASD, and the association between vaccines in general and ASD.

Thimerosal is a mercury-containing organic compound, and since the 1930s, it has been widely used as a preservative in a number of biological and drug products, including many vaccines, to prevent the growth of harmful microbes inadvertently introduced into the vaccine during use.