Researchers are investigating whether the perceived link between autism and vaccines has resulted in lower vaccination rates among the siblings of those with autism.
The perceived link between vaccinations and autism has been a major factor in the lower vaccination rates seen in their siblings in spite of the evidence contradicting this association. In families of children with autism, parents may be more concerned about the association between vaccines and autism since the development of the disorder in future children may be more pronounced.
Gena Glickman and colleagues from the University of California followed 71 infants who have siblings with autism and 135 infants who have siblings without autism. There were no differences in the vaccination rates of the children with autism compared to those without autism. The study showed, however that parents of children with autism were less likely to vaccinate their subsequent children. The results were recently published in the New England Journal of Medicine.
In this study, 83.1% families of children with autism vaccinated their subsequent children, whereas 97.0% of families with children without autism vaccinated their subsequent children. These parents also reported a higher rate of adverse reactions to vaccination in their child with autism (22.6% adverse reaction rate versus a 3.8% rate in families of children without autism). Additionally, parents of children with autism also reported a higher rate of adverse reaction to vaccination in their younger children (6.9% vs 0.8% adverse reaction rate in families of children without autism). These findings may be subject to recall bias since the data are collected retrospectively.
Considering the recent outbreaks of illnesses that are prevented by vaccinations, a better understanding of the risks of vaccinating children is necessary at the public health level. Although larger prospective studies are required to solidify the findings from this current study, it is apparent that the perceived link between autism and vaccination is still a concern, particularly for parents of children with autism. Vaccination rates can possibly be improved in siblings of children with autism if parents have a better understanding of the risks to vaccination.
Written by Jessica Caporuscio, PharmD
Reference: Glickman G, Harrison E, Dobkins K. Vaccination Rates among Younger Siblings of Children with Autism. N Engl J Med. 2017.