Some of the other news coverage like the Reuters article is a little better at correctly pointing this caveat out: https://uk.reuters.com/article/uk-health-polio-africa/wild-p...
It's not even clear that it's poasible to actually eliminate polio in developing countries with this vaccine or any existing vaccines. The developed countries managed it but they had far better infrastructure to roll out first the oral vaccine and then the inactivated vaccine to everyone, and also far better sanitation, and it's likely both of these things mattered - under-vaccination makes this problem a lot worse, and whilst the inactivsted vaccine protects people from polio there's some doubt as to whether it can stop them spreading it via the oral-fecal route due to poor immunity in the gut. The current hope seems to be developing and deploying a new, better live vaccine which cannot easily regain its original virulence.