I'm not trying to be snoopy here, but I thought you said his disability was the result of taking medication to which he had a bad reaction.
"Truly autistic," I would think, would refer to a child born autistic who continued to be autistic -- yes?
Well, we don't know this for certain because--obviously--not every child who received this particular vaccination developed autism. There must have been some sort of predisposition or sensitivity in my brother's genes to have had him react so violently, but for all we know, this could have simply been a physical
reaction and no further mental harm came from it. Indeed, this is likely the loophole the lawyers used when my parents filed a lawsuit and received absolutely no compensation :x