What about Vaccines?
It has been suggested by some that vaccines may be responsible for the increase in the rates of autism. This debate stirs deep emotions and strong-conflict among parents and scientists. From the perspective of main stream science, a connection between vaccines and the increasing rates of autism is not supported by evidence. In fact, the CDC, the American Academy of Pediatrics and the FDA all strongly disavow any link between vaccines and autism. Their position is well supported by a large body of scientific evidence.
An equally large number of parents are convinced that their child became autistic because of vaccinations. Scientists argue that this is a result of the timing of vaccines and of the similar timing of many of the manifestations of autism. Most scientists suggests that because these two events often occur during the same time period, parents assume a cause and effect relationship that does not exist... Likening this assumption to suggesting that the sun rises because the rooster crows.
In any event, the suggested link between vaccinations and autism has been suggested to be the result of either of two different mechanisms. The first mechanism suggested was the presence of the mercury containing preservative, thimerosal in many childhood vaccines (prior to 2001). Mercury is a known neurotoxin, and thus thimerosal became suspect early on in the growing autism epidemic. Since 2001 however, thimerosal was no longer included in the manufacture of childhood vaccines (with the exception of the flu vaccine). By 2003, most remaining vaccines that had included thimerosal had expired (again, except the flu vaccine and tetanus). If thimerosal had been the cause of autism, the numbers of children diagnosed with autism would have been expected to drop as exposure to thimerosal dropped. That has not been the case. Despite a decrease in exposure to thimerosal, autism rates have continued to climb. Additionally, a number of well designed studies have shown no link between thimerosal and autism.
The second mechanism by which vaccines have been suggested to cause autism is the "immune system overload theory". Essentially, proponents of this theory have suggested that a young child's immune system becomes overwhelmed due to the large number of vaccines now given in the early years. The MMR vaccine particularly has been pointed to by the proponents of this theory, and was initially identified as a possible cause of autism by Andrew Wakefield. Andrew Wakefield, a physician in the UK, was roundly criticized for his conclusions by the rest of the scientific community. It turned out that his motives may well have been tainted by money, and that the results he claimed were not replicable by others in the scientific community. Subsequently, large epidemiological studies have found NO link between autism and MMR. Concerns have persisted in the public realm despite evidence to the contrary. Proponents of the autism overload theory have claimed that some of these studies might be flawed, but with over a dozen epidemiological studies in different countries using different techniques and reaching the same conclusion..... most scientists agree there is no link. It seems reasonable to assume that the epidemiological studies rule out the MMR as the sole cause of the rise in autism rates. This of course does not rule out the possibility that there may be very small numbers of children who are genetically predisposed to being susceptible to harm from vaccinations due to genetic predispositions.
The web contains lots of information about Autism, it's risk factors & hypothesized causes. Some sources are very credible, and many others are sheer quackery.... Here are some interesting links from very credible and well respected sources you may want to explore:
National Media Articles and Shows
Concerning Vaccines & Autism
Talk of the Nation (an NPR Show) discusses
Vaccines & Autism.
CNN Video & Article on the Link Between Autism & Vaccines
Businessweek Article on Thimerosal & Autism in California
Information Provided by the CDC and
NIH regarding Vaccines and Autism
CDCs Informational Page on Autism & Vaccines
CDCs Summary Sheet of Studies looking for Autism Vaccine Link
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