The challenge was immense About twenty years ago, India accounted for over 60% of all polio cases worldwide -- in fact it was considered a "hyper" endemic country. Then, the Indian government teamed up with the United Nations and other partners, including through the Global Polio Eradication Initiative, to tackle polio head on. India's vast population, its geographic diversity, and pockets of extreme poverty seriously complicated this effort. But the Indian government and its partners adapted, innovated and above all persisted until they could reach the very last child with the polio vaccine. In 2014, India was officially declared polio-free. There has not been a single case of wild polio in India in over eight years. Today, only three countries remain polio endemic. And as of October, there were fewer than 20 wild polio cases worldwide in 2018. The world is now tantalizingly close to the total global eradication of polio, and India's success in defeating polio within its borders is a big reason why total eradication is within reach Through interviews and archival material, this special episode of Global Dispatches tells you the story of how, against all odds, India eliminated polio. This episode is produced in partnership with the the United Nations Foundation as part of a series that examines successes in multilateral cooperation to tackle great global problems.  Previous episodes in this series include how the world closed the hole in the ozone layer, and how the UN Peacekeeping Mission in Liberia successfully completed its work  in 2015.