The World Health Organization (WHO) has issued a fresh scientific assessment confirming that vaccines do not cause autism, doubling down on decades of research and countering one of the most persistent myths in global health.
The latest review, summarised in a statement titled “WHO expert group’s new analysis reaffirms there is no link between vaccines and autism”, comes from the Organisation’s Global Advisory Committee on Vaccine Safety (GACVS), a panel of international experts established in 1999 to independently assess vaccine safety.
According to WHO, the committee examined evidence from 31 primary research studies published between January 2010 and August 2025 across multiple countries. These studies evaluated both thiomersal-containing vaccines and broader claims about whether any childhood vaccines are associated with autism spectrum disorders (ASD).
The assessment concluded that “based on available evidence, no causal link exists between vaccines and autism spectrum disorders”, reaffirming the Organisation’s long-standing position that childhood immunisation is safe.
The experts also reviewed decades of claims surrounding aluminum adjuvants, ingredients used in small amounts to boost vaccine effectiveness. Drawing on research conducted from 1999 to March 2023, including a major cohort study analysing nationwide registry data of children born in Denmark between 1997 and 2018, GACVS again found no evidence of any association with autism.
“In summary,” the committee stated, “high-quality evidence shows no association between the trace amounts of aluminum used in some vaccines and ASD”, reinforcing conclusions previously issued by GACVS in 2002, 2004 and 2012, each rejecting any link between vaccines and autism.
Following the review, WHO urged governments to base vaccine policy strictly on scientific evidence, saying: “National authorities must ensure that vaccine decisions are grounded in the strongest available data”.
The Organisation emphasised that vaccines remain one of humanity’s greatest public-health achievements. According to WHO, at least 154 million lives have been saved through childhood immunisation efforts over the past 50 years.
The renewed clarification comes amid heightened political debate. In September, U.S. President Donald Trump publicly suggested that pregnant women should avoid Tylenol over an unproven autism link and also called for major changes to childhood vaccination schedules.
WHO responded the next day, reiterating that neither Tylenol nor vaccines have been shown to cause autism.
About the Author
