Autism Not Linked to MMR Vaccine: Study

In recent years, parents have been cautious of getting their child vaccinated for fear that they might develop autism. But parents can rest easy as a new study shows that there is no link between autism spectrum disorder (ASD) and the measles-mumps-rubella (MMR) vaccine.

Though, it should be noted that this study is far from the first to debunk the alleged link between the MMR vaccine and ASD. Nonetheless, parents and others continue to wrongly associate the vaccine with ASD, and blame the vaccine for their children's condition. This belief, combined with knowing that younger siblings of children with ASD are already at higher genetic risk for ASD compared with the general population, might prompt these parents to avoid vaccinating their younger children.

To better get through to parents, a team of scientists studied approximately 95,000 children with older siblings, both with and without ASD, to determine whether the MMR vaccine played a role in the occurrence of ASD. Overall, 994 children had ASD diagnosed during a follow-up.

Among those who had an older sibling with ASD, 6.9 percent were diagnosed with ASD, whereas 0.9 percent were diagnosed with ASD among those without ASD-affected siblings. However, data analysis showed that receiving the MMR vaccine was not associated with an increased risk of ASD at any age, regardless of whether older siblings had ASD.

"Consistent with studies in other populations, we observed no association between MMR vaccination and increased ASD risk among privately insured children. We also found no evidence that receipt of either 1 or 2 doses of MMR vaccination was associated with an increased risk of ASD among children who had older siblings with ASD," the authors wrote in the journal JAMA.

"As the prevalence of diagnosed ASD increases, so does the number of children who have siblings diagnosed with ASD, a group of children who are particularly important as they were undervaccinated in our observations as well as in previous reports," they added. (Scroll to read on...)

The MMR vaccination rate (l dose or more) for the children with unaffected siblings (siblings without ASD) was 84 percent at age 2, while it jumped to 92 percent at age 5. In contrast, the MMR vaccination rates for children with older siblings with ASD were lower - 73 percent at age 2 years and 86 percent at age 5 years.

"Some parents of children with ASD may have chosen to delay immunization in subsequent children until they were certain any risk had passed," Bryan H. King, M.D., from the University of Washington, who was not involved in the study, said in a news release.

"Taken together, some dozen studies have now shown that the age of onset of ASD does not differ between vaccinated and unvaccinated children, the severity or course of ASD does not differ between vaccinated and unvaccinated children, and now the risk of ASD recurrence in families does not differ between vaccinated and unvaccinated children," he concluded.

ASD is defined as a developmental disability that is caused by differences in how the brain functions, causing someone to communicate, interact, behave and learn in different ways, according to the US Centers for Disease Control and Prevention (CDC). Recent estimates show that in the United States, about one in 68 children have been identified with autism.

The CDC itself even agrees with this study's conclusion in that there is no link between vaccines in autism. In fact, in 2011, an Institute of Medicine (IOM) report looked at eight vaccines given to children and adults and determined that these vaccines are very safe.

So parents, maybe it's time to start looking at the facts.

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