Importance Despite research showing no link between the measles-mumps-rubella (MMR) vaccine and autism spectrum disorders (ASD), beliefs that the vaccine causes autism persist, leading to lower vaccination levels. Parents who already have a child with ASD may be especially wary of vaccinations.
Objective To report ASD occurrence by MMR vaccine status in a large sample of US children who have older siblings with and without ASD.
The chart below gives some examples of how disease levels have declined since vaccinations began. Since the introduction of the measles, or MMR vaccine, annual cases of the illness have dropped by a jaw-dropping 99%.