Stephanie Flanders, former BBC economics editor, has a very personal interest in the battle to beat polio. Her father, Michael Flanders, one half of the world-famous singing duo of the 50s and 60s, Flanders and Swann, was paralysed by the infection when he was 21. He used a wheelchair for the rest of his life, and died early at 53 through complications caused by the disease. Stephanie was just six.

In the 2013 Richard Dimbleby Lecture, one of the world's greatest entrepreneurs and leading philanthropists, Bill Gates, explains his optimism for a world free of the debilitating disease, polio. He explains why he is devoting so much of his time, money and influence to eradicating polio, and how we can all help to finish the job.

Unreported World meets the health workers risking their lives to vaccinate children against polio in Pakistan, where the Taliban have issued a decree against vaccination