The Centers for Disease Control and Prevention (CDC) has recently updated its website to suggest that there might be a connection between autism and vaccines. This is a significant change from their long-held stance that there is no link. The idea that vaccines cause autism has been widely discredited by numerous high-quality studies. However, Robert F Kennedy Jr, the US Secretary of Health and Human Services (HHS), has long supported this claim and pushed for more research into it. The CDC’s website now states, as of a November 20 update, that the claim ‘vaccines do not cause autism’ is not based on evidence because studies have not completely ruled out the possibility that infant vaccines could cause autism. The website also notes that this statement has been used in the past to prevent people from being hesitant about vaccines. The CDC plans to update its page with findings from a comprehensive assessment by the HHS on the causes of autism. The website still has a title that reads ‘Vaccines do not cause Autism’, which was added as part of an agreement with Senator Bill Cassidy to secure RFK Jr’s confirmation. However, this statement is contradicted by the information listed before it. Senator Cassidy, a doctor, wrote on LinkedIn on November 20 that parents need to know that vaccines for diseases like measles, polio, and hepatitis B are safe and effective and do not cause autism. He called any statement suggesting otherwise wrong and irresponsible. The psychiatric, infectious disease, and autism communities also criticized the CDC’s new stance. The American Public Health Association (APHA) expressed alarm that the CDC is promoting the outdated and disproven idea that vaccines cause autism. The Infectious Diseases Society of America (IDSA) stated that decades of research have proven that vaccines do not cause autism and that the CDC’s sudden change is reckless and harmful. In July 2025, the IDSA was one of several organizations that sued RFK Jr and the HHS over changes to the national immunization schedule and the CDC’s vaccine panel of experts. Alison Singer, president of the Autism Science Foundation, said that the facts do not change just because the administration does. She emphasized that the existing data clearly shows no link between vaccines and autism and that the administration is ignoring this data.