Environmental Factors (2009) - Childhood Vaccines Reading Guide

Gerber & Offit, 2009 Environmental Factors – Childhood Vaccines

Gerber, J. S. & Offit, P. A. (2009). Vaccines and autism: A tale of shifting hypotheses. Clinical 

Infectious Diseases, 48(4), 456-461. 

The purpose of this article is to summarize the research that has been done to determine if childhood vaccines cause ASD. In 1998 a researcher named Andrew Wakefield and several of his colleagues published a study in a very prestigious researcher journal called the Lancet that indicated that childhood vaccines caused (may cause) ASD. As the result of this study, many parents believed (and some still believe) that their child’s ASD was caused by childhood vaccines. Since 1998, many studies have been undertaken to further determine whether that Wakefield’s findings were true. This article provides some of that history and evaluations of the research on this topic to date. Although not discussed in this article, as more information came out about Wakefield’s original study, his article was retracted from the Lancet (this research has been found to be faulty) and he lost his Medical License. You can read more about this in the optional article in your Module 3 folder (if you are interested). 

1. What were the three hypotheses proposed regarding a possible link between vaccines and ASD. 

• the combination measles-mumps-rubella vaccine causes autism by damaging the intestinal lining, which allows the entrance of encephalopathic proteins

• thimerosal is toxic to the central nervous system

• the simultaneous administration of multiple vaccines overwhelms or weakens the immune system

2. What is Thimerosal?      

• an ethylmercury-containing preservative in some vaccines

• 50% ethylmercury by weight

• antibacterial compound that has been used effectively in multidose vaccine preparations for over 50 years

• not contained in live-virus vaccines

3. Describe briefly what the theory regarding Thimerosal and the impact on ASD?      

• the connection between thimerosal and its impact on ASD, is maily due to the ethylmercury contained within thimerosal

• Mercury poisoning was proven not to cause ASD though

4. Give 4 reasons why the theory on “Too Many Vaccines” were described as flawed.

• ASD is a neurodevelepmental disorder so no one is a “susceptible host”

• Vaccines stregthen the immuge system, not weaken it

• ASD is not an immune-mediated disease

• No studies have shown a connection between the rise of vaccines and ASD diagnoses

5. What is your take-away message from this article?      

• Vaccinations and ASD do not, as of now, have causation between them.