The World Health Organization has released a fresh review confirming that vaccines do not cause autism pushing back against misinformation circulating in the United States.
The US Centers for Disease Control and Prevention recently updated parts of its website with wording that appeared to soften its long-standing, evidence-based stance that vaccines are not connected to autism. This shift has stirred concern among scientists and public health experts.
Extensive global studies over many years have consistently shown no causal relationship between vaccines and autism or any other developmental conditions. Despite this, US health chief Robert F. Kennedy Jr. has repeatedly amplified anti-vaccine narratives that wrongly suggest a link.
At a press briefing in Geneva, WHO Director-General Tedros Adhanom Ghebreyesus restated the agency’s position: autism is not a vaccine side effect. He highlighted a new analysis by the Global Advisory Committee on Vaccine Safety, which examined 31 studies from several countries over the past 15 years, including research on thiomersal a preservative used in multidose vials and aluminium-based adjuvants.
According to Tedros, the committee found no evidence tying any vaccine ingredients, including aluminium or thiomersal, to autism. This marks the fourth comprehensive review since 2002, all of which reached the same conclusion.
Tedros acknowledged that vaccines, like all medical products, can cause side effects but autism is not one of them.
The misconception linking the MMR (measles, mumps and rubella) vaccine to autism originated from a 1998 study that was later proven fraudulent and fully withdrawn. Although discredited, its false claims continue to fuel vaccine hesitancy.
Kennedy, a prominent voice in anti-vaccine circles and a key figure in the “Make America Healthy” movement within Donald Trump’s political base, has long promoted misinformation on the topic. The recent CDC website changes triggered frustration among scientists, including within the agency itself, who have spent decades countering such myths.
Tedros also pointed to the major achievements of global immunisation efforts. In the last 25 years, deaths among children under five have dropped from 11 million annually to 4.8 million largely because of vaccines.
“Vaccines are one of the most powerful breakthroughs in human history,” he said, noting their role in preventing around 30 diseases, from measles and malaria to cervical cancer.