I don't think that counts, because nobody wants to keep polio around, nor does eliminating your own country's polio disadvantage you in any way. Also, it's not as if the elected politicians of each country got together and negotiated an effort to end polio- it was more a concerted effort by WHO, UNICEF, CDC, et al. They just did it under the (correct) assumption that the political entities of the world weren't going to try and stop them.

There are only negative consequences for not participating in polio eradication, and those consequences require no effort from complying participants.

Refusing to participate in a ban on AGI research could be very lucrative, and imposing negative consequences would require a lot of effort for complying participants.

It's lucrative up until someone leaves their fine tuned "make me money" LLaMA instance running over night and it decides to cash out on its airline puts by simultaneously encrypting every ATC system.

Or the banning of CFCs and other ozone depleting substances.

It helped that the benefit/cost ratio was enormous.

Not a valid comparison because there is no incentive to dissent. Unlike with nuclear arms or AI, there is an incentive to dissent, because being the only group with access to this tech is an advantage.

Nobody had an economic interest in the continued spread of polio. (well, crutch manufacturers perhaps? probably not a powerful lobby.)

Also, we're currently failing at polio eradication. It has had a resurgence in 2022 and 2023, and there is no political will to finish the job.

Smallpox is eradicated, except for the samples kept at the CDC and wherever Russia keeps their samples. IIRC high-ranking US officials still get the smallpox vaccine. Just in case.