A new study provides further evidence that the measles-mumps-rubella vaccine is not associated with an increased risk of autism. Concerns that the MMR shot could cause autism were first raised a decade ago by British physician Andrew Wakefield, who, based on a study of 12 children, proposed that there was a link between the vaccine and bowel disease and autism. That research has since been widely discredited, and numerous international studies have failed to find a connection between MMR vaccination and autism. This latest study included 96 Polish children ages 2 to 15 who had been diagnosed with autism. Researchers compared each child with two healthy children the same age and sex who had been treated by the same doctor. Some of the children had received the MMR vaccine, while others had not been vaccinated at all or had received a vaccine against measles only. Overall, the study found, children who had received the MMR vaccine actually had a lower risk of autism than their unvaccinated peers. Nor was there any evidence of an increased autism risk with the measles-only vaccine. The study does not answer the question of why vaccinated children had a lower autism risk. But one possibility, according to the researchers, is that some children started showing potential signs of autism, or possibly other health problems, before receiving the MMR or measles vaccine. Doctors or parents may then have avoided vaccination.
