I agree with you saying that we need to keep exploring and developing cures and vaccines, but please note that it's not false that we do have a (very effective) vaccine for poliovirus.

The fact that this virus belongs to a bigger family (with other viruses such as Coxsackie, echo, etc) doesn't mean that they're all as nasty as polio. Think of the smallpox and its vaccine: it was a different virus from the same family that allowed smallpox to be eradicated.
The fact that another virus such as the novel enterovirus can cause the same syndrome as polio doesn't mean that it's the same rose going by a different name; they are related, sure, belonging to the same family, but they are way, way more different than two different influenza strains (that are already so different that we need a new vaccine every year). They have very different infection rates and the percentage of afps complications is much lower.

Polio vaccine IS a story of success. This is a virus that can be eradicated, much like the smallpox, because it is not transmitted by other animals. If we keep vaccinations rates up, this disease could disappear everywhere.