MMR vaccine
The CDC, the IOM of the National Academy of Sciences, Australia's Department of Health, and the UK National Health Service have all concluded that there is no evidence of a link between the MMR vaccine and autism. A Cochrane review concluded that there is no credible link between the MMR vaccine and autism, that MMR has prevented diseases that still carry a heavy burden of death and complications, that the lack of confidence in MMR has damaged public health, and that the design and reporting of safety outcomes in MMR vaccine studies are largely inadequate. Additional reviews agree, with studies finding that vaccines are not linked to autism even in high risk populations with autistic siblings.