WHO study confirms vaccines do not cause autism

GENEVA — A new analysis by the World Health Organization’s (WHO) Global Advisory Committee on Vaccine Safety (GACVS) has found no causal link between vaccines and autism spectrum disorders (ASD), reaffirming the global health body’s long-standing position on vaccine safety.

The latest findings, discussed by the Committee on Nov. 27, 2025, reviewed evidence from 31 primary research studies published between January 2010 and August 2025.

The data — covering childhood and pregnancy-related vaccinations across multiple countries — strongly confirm that vaccines do not cause autism.

The Committee first examined concerns about thiomersal, a mercury-based preservative used in some vaccines.

It found no evidence supporting a link between thiomersal-containing vaccines and ASD.

In addition, GACVS reviewed data on vaccines in general, concluding that there is no association between any childhood vaccines and autism.

“The available high-quality evidence shows no association between the trace amounts of aluminum used in some vaccines and ASD,” the Committee stated.

This conclusion followed an extensive review of health risks linked to aluminum adjuvants — substances added to vaccines to enhance immune response — based on studies conducted from 1999 through March 2023.

The Committee also evaluated a recent large-scale cohort study that analyzed nationwide registry data of children born in Denmark between 1997 and 2018.

This robust dataset reinforced the conclusion that there is no credible link between vaccines and autism.

As a result, the Committee reaffirmed its previous conclusions from 2002, 2004, and 2012, stating that “vaccines, including those with thiomersal and/or aluminum, do not cause autism.”

WHO is urging governments and national health authorities to base their vaccination policies on the latest scientific evidence and not on misinformation.

“Global childhood immunization efforts represent one of the greatest achievements in improving lives, livelihoods, and the prosperity of societies,” WHO said in its statement.

According to the WHO, immunization has saved at least 154 million lives over the past 50 years.