Two studies have been cited by those claiming that the MMR vaccine causes autism. Both studies are critically flawed. Autism has been studied for decades, including its causes. As with other conditions, when we don’t understand their cause, many things can be considered as the cause. For many years, people have questioned things that babies are exposed to before birth or in the early months of life. This includes environmental exposures to things like acetaminophen during pregnancy and vaccines in the first few months of life. In both cases, study after study have shown these hypotheses to be unsupported by the science. The evidence has not stopped some from continuing to speculate about them. Over time, scientists have found some of the causes, including genetic links, certain viral infections, and parental age, but because autism covers a spectrum of disorders, there will not be a single cause. On this page, we discuss the original studies that suggested vaccines, specifically the MMR vaccine, as a cause of autism; other studies that have since disproven that hypothesis; and some of what we know about the causes of autism. The page also includes a variety of resources and references to some of the seminal studies related to vaccine and autism.