Immunizations and autism: A review of the literature
ABSTRACT Because of a temporal correlation between the first notable signs and symptoms of autism and the routine childhood vaccination schedule, many parents have become increasingly concerned regarding the possible etiologic role vaccines may play in the development of autism. In particular, some have suggested an association between the Measles-Mumps-Rubella vaccine and autism. Our literature review found very few studies supporting this theory, with the overwhelming majority showing no causal association between the Measles-Mumps-Rubella vaccine and autism. The vaccine preservative thimerosal has alternatively been hypothesized to have a possible causal role in autism. Again, no convincing evidence was found to support this claim, nor for the use of chelation therapy in autism. With decreasing uptake of immunizations in children and the inevitable occurrence of measles outbreaks, it is important that clinicians be aware of the literature concerning vaccinations and autism so that they may have informed discussions with parents and caregivers.
- SourceAvailable from: Andreas M Grabrucker
- "However, the evidence for these risk factors, such as gastrointestinal or immune system abnormalities, allergies, and exposure of children to drugs, infection, certain foods, or heavy metals needs further substantiation. Vaccination can no longer be regarded as risk factor for autism (Doja and Roberts, 2006). Evidence from several rigorous scientific studies examining an association between vaccine use and autism have not identified such a link (Miller and Reynolds, 2009) and the data of former studies claiming an association were shown to be scientifically fraudulent (Flaherty, 2011). "
Article: Environmental Factors in Autism[Show abstract] [Hide abstract]
ABSTRACT: Autism is a neurodevelopmental disorders characterized by impairments in communication and social behavior, and by repetitive behaviors. Although genetic factors might be largely responsible for the occurrence of autism they cannot fully account for all cases and it is likely that in addition to a certain combination of autism-related genes, specific environmental factors might act as risk factors triggering the development of autism. Thus, the role of environmental factors in autism is an important area of research and recent data will be discussed in this review. Interestingly, the results show that many environmental risk factors are interrelated and their identification and comparison might unveil a common scheme of alterations on a contextual as well as molecular level. For example, both, disruption in the immune system and in zinc homeostasis may affect synaptic transmission in autism. Thus, here, a model is proposed that interconnects the most important and scientifically recognized environmental factors. Moreover, similarities in how these risk factors impact synapse function are discussed and a possible influence on an already well described genetic pathway leading to the development of autism via zinc homeostasis is proposed.Frontiers in Psychiatry 11/2012; 3:118. DOI:10.3389/fpsyt.2012.00118
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- "Because those data pertain primarily to children, and cognitive outcomes of Hg toxicity may vary with developmental stage at exposure, effects of thimerosal are beyond the scope of this paper. Detailed reviews are available elsewhere (Clements & McIntyre, 2006; Doja & Roberts, 2006; Nelson & Bauman, 2003). "
ABSTRACT: A 63-year-old man with a history of alcohol dependence ingested elemental mercury as a suicide gesture. Serial abdominal X-rays showed gradual but incomplete clearance of mercury from the colon. Routine chest X-ray showed evidence of punctate radiopaque materials in the lower lobe of the right lung. Blood and urine mercury levels both exceeded thresholds considered to be associated with cognitive dysfunction. Elicited cognitive deficits were most prominent in processing speed, flexibility, and response inhibition. Semantic fluency, visuospatial processing, and recall memory for visual and low-context verbal material were also affected. The deficits may have been attributable primarily to alcohol abuse. Elemental mercury is not readily absorbed from the gastrointestinal tract; however, mercury vapor, which was inhaled inadvertently, readily crosses the blood-brain barrier and is neurotoxic. We argue, therefore, that mercury toxicity is more likely than not to have been a factor contributing to the patient's cognitive dysfunction.Applied Neuropsychology 02/2008; 15(1):79-91. DOI:10.1080/09084280801917889 · 1.97 Impact Factor
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ABSTRACT: To educate pharmacists regarding the hypothesis that the measles-mumps-rubella (MMR) vaccine is linked to the development of autism. Articles published from 1998 to 2009 were identified through electronic searches of Medline. Articles were included if they evaluated or reviewed a possible link between the MMR vaccine and autism or discussed MMR epidemiology, legal proceedings involving the MMR vaccine and autism, or health professionals' impact on immunization decisions. A total of 27 articles were identified. Of the articles, 74% (20 of 27) were included in the review because of their relevance to the study topic. The evidence presented does not show a causal relationship between the MMR vaccine and autism. Myths presented to potentially support any relationship between the MMR vaccine and autism have not been proven. Expert testimony refuting initial scientific theories has led to Supreme Court decisions that do not support a link between the MMR vaccine and autism. Pharmacists and all health care providers are responsible for informing and educating parents and families regarding this information so that they can make informed decisions about immunizations.Journal of the American Pharmacists Association 11/2010; 50(6):736-41. DOI:10.1331/JAPhA.2010.10004