Egyptian Study on Autism and Vaccines
WHAT IS THE TRENDING NEWS STORY
An article appeared in February 2017 claiming that a team of nine Egyptian scientists may have just confirmed that one in every 50 American children has autism, and its primary cause could be mercury in vaccines.
WHY THE STORY HAS MISINFORMATION
This wasn’t the first study to claim that. In 2016 during another Egyptian study, researchers were trying to assess the relationship between mercury levels and autism, and their results showed a positive linear relationship between mercury levels and the severity of autism symptoms.
These claims can be answered by one sentence, but let's go through the scientific method step by step.
The first important point is; these scientists couldn’t prove the causation between mercury levels and autism. They also didn’t confirm the source of mercury. While the study in question suggested it was from the vaccines at early ages, other studies also found elevated mercury, lead, and aluminum levels in children with autism, but it was suggested that it was most probably from maternal fish consumption, living near gas stations, and/or usage of aluminum paints during the key times of these children's development.
Furthermore, one of these studies themselves found that environmental exposure, as well as the genetic inability of certain children to excrete metals, could be the reason for the high levels of heavy metals, such as mercury, in these children.
On the other hand, researchers in metropolitan Atlanta compared 624 children who have autism with 1,824 healthy children. After reviewing vaccination records from state immunization forms, they found no differences in age at vaccination between autistic and non-autistic children, which suggests that vaccine exposure was not a risk factor for autism.
In Finland, researchers performed 2 prospective cohort studies where they recorded adverse events associated with measles, mumps, and rubella (MMR)-vaccinated children during 1982–1996, and discovered that none of the children developed autism. Additionally, a further analysis of this study revealed no association between vaccines and autism among 1.8 million children.
Mercury in vaccines
One of the vaccine components was thimerosal — 50% ethylmercury, a mercury-based antibacterial compound that has been used effectively in multi-dose vaccine preparations for more than 50 years to prevent contamination of vaccines. It has been studied specifically and several research studies showed that thimerosal does not cause autism. For instance, a scientific review by the Institute of Medicine (IOM) found that all pieces of evidence pointed out to no causal relationship between thimerosal–containing vaccines and autism.
Since 2003, CDC funded or conducted 9 studies around the world, and no association between thimerosal-containing vaccines and autism was found, as well as no link between the MMR vaccine and autism in children. A final CDC study in 2013 also found no direct relation between vaccines and autism.
The most important fact to mention is; In 1997, the US Food and Drug Administration Modernization Act mandated identification and quantification of mercury in all food and drugs; 2 years later, the US FDA found that children might be receiving as much as 187.5 µg of mercury within the first 6 months of life. Despite the absence of data suggesting harm from quantities of ethylmercury contained in the vaccines, in 1999, the American Academy of Pediatrics and the Public Health Service recommended the immediate removal of mercury from all vaccines given to young infants. Between 1999 and 2001, thimerosal was removed or reduced to trace amounts in all childhood vaccines except for some flu vaccines. It was done as a precaution to reduce all types of mercury exposure in children before studies were conducted that determined that thimerosal was not harmful. Currently, the only childhood vaccines that contain thimerosal are flu vaccines packaged in multi-dose vials. However, thimerosal-free alternatives are also available for the flu vaccine.