No Autism Association with MMR Vaccine, Study Affirms

While many parents remain concerned that the measles-mumps-rubella (MMR) vaccine could cause their children to develop autism, a study has reaffirmed there is no link between the vaccine's use and increased autism risk.

While many parents remain concerned that the measles-mumps-rubella (MMR) vaccine could cause their children to develop autism, a study has reaffirmed there is no link between the vaccine’s use and increased autism risk.

The study, which was published in JAMA, analyzed data from approximately 95,000 US children, including 2.01% of whom had an older sibling with an autism spectrum disorder (ASD), putting them at increased risk of developing one.

The research team discovered 1.04% of participants were diagnosed with an ASD. Among the children who had an older sibling with an ASD, 6.9% developed one, as well, compared with 0.9% of those who did not have an older sibling with an ASD.

After examining the incidence of ASD and the frequency of MMR vaccination, the researchers determined the MMR vaccine was not associated with an increased risk of ASD at any age, even among those who had a sibling with an ASD.

“Consistent with studies in other populations, we observed no association between MMR vaccination and increased ASD risk among privately insured children,” the study authors wrote. “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 noted children who had older siblings with an ASD were particularly undervaccinated, as the MMR vaccination rate for these participants was 73% and 86% at age 2 and 5, respectively. Comparatively, the vaccination rate for children with unaffected siblings was 84% and 92% at age 2 and 5, respectively.

This is the latest piece of research to dismiss the connection between the MMR vaccine and autism—a claim believed to originate from a 1998 study published in The Lancet. The journal later retracted the study, and its lead author, Andrew Wakefield, was barred from practicing medicine in the United Kingdom.

“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,” wrote Bryan H. King, MD, MBA, of the University of Washington and Seattle Children's Hospital, Seattle, in an accompanying editorial.

In an exclusive interview with Pharmacy Times, vaccine expert Stephan Foster, PharmD, FAPhA, FNAP, of the University of Tennessee College of Pharmacy, encouraged pharmacists to use motivational interviewing techniques, such as active listening, to convince skeptical parents to vaccinate their kids, rather than attempting to scare or pressure them.

“Empathy and respect are absolutely integral when speaking with hesitant parents,” Dr. Foster told Pharmacy Times. “Pharmacists should listen to patients’ perspectives, reassure them that many people share their concerns, and ask them if they would like information that might alleviate their fears.”

Pharmacists should be patient but persistent in these interactions, as skeptical parents are unlikely to change their views after a single interaction, Dr. Foster previously noted.

Dr. Foster ultimately emphasized that pharmacists should always take the opportunity to discuss the importance of vaccination, regardless of a patient’s stance.

“It is essential that pharmacists talk to patients and take the time to explain to them the benefits of vaccines,” Dr. Foster said. “Pharmacists can play a significant role not only in treating individual patients, but also in advancing preventative care and public health.”