NEW YORK (Reuters Health) - Immunization with the measles, mumps, and rubella (MMR) vaccine doesn't seem to raise a person's odds of developing autistic spectrum disorder (ASD), which includes autism and similar disorders, new research suggests.

Dr. Kumanan Wilson, from Toronto General Hospital, and colleagues reviewed the findings from previous studies to determine whether the MMR vaccine might cause ASD.

The new findings are reported in the Archives of Pediatrics and Adolescent Medicine.

Twelve studies from five countries were included in the review. One study compared the rate of ASD in children who received the MMR vaccine with the rate in unvaccinated children. In this study, neither group was more likely than the other to develop ASD.

Six more studies looked at how vaccination rates changed over time and again found no evidence that the MMR vaccine leads to ASD.

Four studies, which focused on certain kinds of ASD, also found no link between vaccination and ASD.

In addition, in vaccinated children who developed ASD, vaccination did not always precede the development of ASD, meaning that it could not have caused the disorder.

Still, it is possible that some form of ASD may be associated with vaccination. If so, however, "it is sufficiently rare so as not to be identified by the current epidemiological studies," the authors note.