This should hardly be surprising news, as he panders to just about every other kook group that could get him elected, but McCain recently came out and supported the repeatedly disproved “vaccines cause autism” crowd (or at least that a mercuric compound in vaccines, thimerosal, allegedly causes autism).
The Bad Astronomer comments, and gives links to a few other folks’ comments too.
The biggest indicator that thimerosal is not guilty? In the USA, thimerosal was ordered to be removed from most vaccines in 1999, but there has been no drop in autism diagnoses, in fact the rate of diagnoses has increased substantially since the removal of thimerosal. Most scientists already believed it was not the culprit, but surely anyone with an ounce of logic should see that this reverse correlation pretty much eliminates thimerosal as a suspect?
I can totally understand people whose child/ren are diagnosed with an autistic spectrum disorder wanting an explanation. When my son was diagnosed as High Functioning Autistic/borderline Aspergers at age 3, I desperately wanted an explanation and considered the vaccine hypothesis myself. I read a lot and came to agree with the bulk of medical opinion that there is no connection, merely a temporal coincidence: the symptoms of autism (a congenital neurological variation) become most obvious in young children at about the same age as routine vaccinations are scheduled.
A particular cognitive developmental milestone occurs around the age of 18 months to 2.5 years, which in neurotypical children manifests as marked progress in communication and socialisation skills as they find their cognitive array enhanced – their brain is processing external stimuli in a more efficient fashion and they are responding with increased engagement with those external stimuli. Neurologists are finding that with autistic children, this communication/socialisation progress does not occur, largely because the autistic brain is hypersensitive to external stimuli as well as processing these stimuli differently, leading to autistic children experiencing sensory overload to various degrees and coping with it by withdrawing from the overload in various ways.
Sometimes children who were very chatty in an infantile way regress to using fewer words, as well as becoming markedly less sociable and starting to push away from physical contact with their family as well. Obviously, to the concerned parent, this looks like some external factor has made their child change, when what is actually happening is that a brain that has been atypical from birth is responding differently to enhanced cognition than neurotypical children do.
So, children on the autistic spectrum start to display differences from their neurotypical peers between the age of 18 months to 3 years, which is when they go for assessment and become diagnosed for the first time as autistic, or Aspergers, or PDD-NOS, or Semantic Pragmatic Disorder, or HFA. The more severe the autistic disorder, the earlier the diagnosis. Children with HFA or Aspergers or SPD are often not diagnosed until much later in their schooling, and many adults now are finding that they have an Autistic Spectrum Disorder that nobody diagnosed when they were young.
The expert consensus is that children are born with atypical autistic brains, but the differences in cognition are higher level differences, so that in infancy and very early childhood the brain is too immature for the differences to be obvious. Autistic spectrum disorders seem to run in families in a complicated heredity pattern which most likely indicates that autism is carried on multiple genes which interact in a variety of ways depending on how many have been inherited. There may also be some environmental factor which is causing mutations to the genes which regulate autism, but if so it is a mutagen which affects the parents’ genetic material which they then pass on to their offspring, not a pathogen which affects children directly.
Vaccines are not to blame, and there’s a strong public health risk in people being too fearful to vaccinate their children against serious life-threatening diseases. For a potential President of the USA to be promoting this pseudoscience will mean that this belief will be seen as more acceptable, and will likely spread. For shame, McCain.