Autism rare before mass DPT vaccination
[back] Autism increase

See: Autism and genetics  change in diagnosis

DISCOVERING AUTISM: LEO KANNER IN 1943
An Extremely Rare Disorder

“Since 1938, there have come to our attention a number of children whose condition differs so markedly and uniquely from anything reported so far that each case merits—and, I hope will eventually receive—a detailed consideration of its fascinating peculiarities....

“These characteristics form a unique “syndrome”, not heretofore reported, which seems to be rare enough, yet is probably more frequent than is indicated by the paucity of observed cases.”
-Leo Kanner, “Autistic disturbances of affective contact”, Nervous Child, 1943

“The fact that an average of not more than eight patients per year [over twenty years] could be diagnosed with reasonable assurance as autistic in a center serving as a sort of diagnostic clearinghouse, speaks for the infrequency of the disease, especially if one considers that they recruit themselves from all over the North American continent...”
-Leo Kanner, “The specificity of early infantile autism” Acta Paedopsychiatrie, 1958