The World Health Organization’s top vaccine safety advisory body has issued a categorical reaffirmation that vaccines do not cause autism, a position directly countering recent comments by US Health Secretary Robert F. Kennedy Jr. and a controversial change on the US Centers for Disease Control and Prevention (CDC) website.

In a statement released on Thursday, WHO said a “new analysis from a WHO global expert committee on vaccine safety has found that, based on available evidence, no causal link exists between vaccines and autism spectrum disorders (ASD). The conclusion reaffirms WHO’s position that childhood vaccines do not cause autism.”

The Global Advisory Committee on Vaccine Safety (GACVS), established in 1999 and comprising international experts who provide “independent and authoritative scientific advice,” reviewed evidence from 31 primary research studies published between January 2010 and August 2025. According to the statement, this evidence, covering data from multiple countries “strongly supports the positive safety profile of vaccines used during childhood and pregnancy, and confirms the absence of a causal link with ASD.”

The Committee also examined concerns surrounding aluminum adjuvants. It assessed findings “from studies conducted from 1999 through March 2023,” as well as “a recent large cohort study analyzing nationwide registry data of children born in Denmark between 1997 and 2018.” WHO said the “available high-quality evidence shows no association between the trace amounts of aluminum used in some vaccines and ASD, supporting the ongoing use of vaccines with aluminum adjuvants.”

Following the review, WHO emphasized that GACVS “reaffirms its previous conclusions from 2002, 2004 and 2012: vaccines, including those with thiomersal and/or aluminum, do not cause autism.”

The strong restatement of scientific consensus comes as Health Secretary Robert F. Kennedy Jr. claimed in a New York Times interview that he personally instructed the CDC to alter its longstanding position on the subject. The agency’s website was subsequently changed to state: “The claim ‘vaccines do not cause autism’ is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.”

WHO, without naming US authorities, urged governments to rely strictly on science, noting: “WHO advises all national authorities to rely on the latest science and ensure vaccine policies are grounded in the strongest available evidence.” It added that global childhood immunization remains “one of the greatest achievements in improving lives, livelihoods and the prosperity of societies,” estimating that vaccines have saved “at least 154 million lives” in the past half-century.

Growing vaccine hesitancy and scepticism

Vaccines have often been called the single greatest innovation of the 20th century. The WHO has estimated that in the 50 years since 1974, vaccines have saved 15.4 crore lives. “That’s six lives a minute, every day, for five decades,” it elaborated in a statement.

Yet, sceptics continue to peddle conspiracy theories that these lifesaving interventions could, in fact, cause harm, most notably, it causes autism. Earlier this year, US Health Secretary Robert F. Kennedy Jr. made almost identical claims during an appearance on The Tucker Carlson Show. Kennedy alleged that vaccines, particularly the hepatitis B shot given in early infancy, dramatically increase the risk of autism. These were debunked earlier too.

In the video, Kennedy cited a 1999 analysis he attributed to CDC researcher Thomas Verstraeten, claiming the study found an “11,135 per cent elevated risk of autism” in children who received the hepatitis B vaccine within the first 30 days of life compared to those who were vaccinated later or not at all. He further alleged that the CDC “kept the study secret” and manipulated it across multiple versions to hide a supposed vaccine–autism link.

Kennedy also asserted that “over a hundred studies” in the broader scientific literature support his position, echoing the same narrative now circulating through the McCullough Foundation report shared by Nicolas Hulscher and amplified by Sridhar Vembu.

The same claim was even echoed by US president Donald Trump in the past. “Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn’t feel good and changes – AUTISM. Many such cases!,” Trump tweeted in 2014.

In India, too, earlier this year, a prominent CEO and YouTuber falsely claimed that vaccines are possibly reducing lifespan as well.

Such unsubstantiated claims by prominent and influential persons, coupled with policy decisions such as the US’ National Institute of Health cutting funds meant for research into vaccine hesitancy and removing vaccines from recommended schedules, have compounded the issue of vaccine hesitancy, with devastating consequences.

“Outbreaks of vaccine-preventable diseases such as measles, meningitis and yellow fever are rising globally, and diseases like diphtheria, that have long been held at bay or virtually disappeared in many countries, are at risk of re-emerging,” according to the WHO, which added that “the number of children missing routine vaccinations has been increasing in recent years, even as countries make efforts to catch up children missed during the pandemic.”

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