[TangoLimaSierra]

DDT was banned before the vax was available the Polio rates fell

DDT was banned in the 70s. There were some limitations on its usage in the late 50s and 60s but no outright ban till later. The gov't was still using it until 1970.

[LS]

Maready’s reference was to the states such as MA where it was banned earlier that had an outbreak of Polio. Worth reading his book. Pretty sure, at any rate, that Polio began trending down before the first vax.