Under-vaccination Common Among Children With Autism Spectrum Disorder, and Their Siblings

Under-vaccination is a major problem facing the Autism Community

There’s a particularly insidious effect of the anti-vaccination movement that becomes starkly evident with this study, appearing in the journal JAMA Pediatrics. Kids with autism, and their siblings, are less likely to be vaccinated after the diagnosis.

The study used data from the Vaccine Safety Datalink – this is a continually-updated database that tracks vaccination rates and a host of other factors across 8 comprehensive healthcare sites around the country (though quite a few of the 8 are Kaiser sites in California).

Using validated diagnosis codes, the researchers identified 3,729 children with Autism Spectrum Disorder – a huge number for this type of research – and 592,907 children without a diagnosis. They then looked at vaccination rates over time.

At 4-6 years of age, just 5.9% of the control kids were under-vaccinated (which means they did not receive all of the recommended vaccinations within the recommended time interval). In contrast, 18.4% of the kids with Autism were under-vaccinated.

The findings reached down into the siblings of kids with autism as well. Again at 4-6 years, just over 5% of the control siblings were under-vaccinated compared to 17% of the siblings of kids with autism.

So – why is this happening? There are essentially 2 possible interpretations of the data. One is that factors that lead families to under-vaccinate children are associated with Autism. You could make an argument for this, autism rates are higher among older parents, for instance, who might have more fixed beliefs about vaccination schedules.

But the more likely explanation, in my opinion, is that once a family has a child with autism, the persistent and, let me just say it, false information linking autism with vaccination makes them gun shy both for their child affected with the syndrome, and for siblings down the line.

This is not good. Kids with autism are more likely to be hospitalized than other children, and might have a higher risk of infection. Vaccines may be particularly beneficial in this cohort. Moreover, the increasing networks of parents and kids with autism, so positive for providing support, may represent an epidemiologic risk factor if a high proportion of undervaccinated children are aggregating together. It is sad to see that a movement based on discredited and occasionally fraudulent data has adversely affected healthy kids.

But there’s something even worse when you see anti-vax beliefs negatively impact the very kids these organizations purport to be championing.