“Too many vaccines and autism” is debunked

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Based on false science, many parents think that refusing or delaying vaccinations will be safer for their children and decrease the risk of autism.  While the scientific underpinnings for such a concept have no basis (Pediatrics 2004; 114: 793-804, and Institute of Medicine. Immunization safety review: vaccines and autism. Washington, DC: National Academies Press; 2004), lingering concerns persist.  Into this background, another rigorous study (J Pediatr 2013; 163: 561-7) has concluded that there is “no association between exposure to antigens from vaccines during infancy and the development of autism spectrum disorder (ASD),” autism, or ASD with regression.

So how did the authors reach this conclusion?

Using a case-control study from three managed care organizations (MCOs) of 256 children with ASD and 752 control children, the authors examined exposure to total antibody stimulating proteins and polysaccharides from vaccines.  They utilized vaccine registries and medical records.  The children in this study were born between 1994-1999 and were aged 6-13 years at the time of data collection.

The results showed that with each 25-unit increase in total antigen exposure, the adjusted odds ratio (aOR) for ASD was 0.999 for cumulative exposure to age 3 months. The aOR stayed the same at 7 months and 2 years.  When autism or autism with regression were examined, similarly there was no increased risk.

One of the strengths of this study was that members of these MCOs have routine immunizations as a covered benefit; this helps minimize socioeconomic factors which could influence results.  A small number of ASD cases (5%) and controls (2%) had an older sibling with autism; results were unchanged when these children were excluded.

In many ways, this finding is completely anticipated and in agreement with the Institute of Medicines most recent 2013 report on immunizations (The Childhood Immunization Schedule and Safety: Stakeholder …).  As the authors note in their discussion, “beginning at birth, an infant is exposed to hundreds of viruses and other antigens, and it has been estimated that an infant theoretically could respond to thousands of vaccines at once.”

Bottom-line: Vaccines prevent disease without causing autism.  Vaccine refusal increases the risk of disease for those who refuse and creates collateral damage as well.

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