Will resolve to YES if the Global Polio Eradication Initiative (GPEI), WHO, or another qualified organization certifies the world as being free from polio before 2027.

From https://polioeradication.org/news-post/the-endgame-what-will-it-take-to-eradicate-polio/:

In 2020, GPEI launched a new roadmap to polio eradication, which set out two ambitious targets: firstly to permanently interrupt all poliovirus transmission in Pakistan and Afghanistan, stop transmission of cVDPV and prevent outbreaks in non-endemic countries by 2023. The second target is to certify the world free from polio – meaning no cases have been detected for three years – by 2026.