The United Nations said it was confident of stopping the spread of polio in Nigeria by the end of the year as it races to stem an epidemic fuelled by a 10-month ban on vaccinations in a northern state. The predominantly Muslim state of Kano lifted the boycott last month and restarted polio immunisations, but not before the crippling virus had spread across Nigeria and had also infected 10 African states previously declared polio-free. Kano's state government banned the vaccines last September over fears they had been adulterated with HIV and infertility agents by Western powers trying to depopulate the Islamic world. Gerrit Beger, spokesman for the United Nations children's agency UNICEF, said 58 percent of 4.1 million children in Kano had been vaccinated after a July immunisation drive. Three more campaigns were planned over the next three months. Beger said Kano needed to immunise at least 90 percent of children in the state to stop polio spreading and was confident that figure could be reached by October. Nigeria now accounts for three-quarters of the new polio infections worldwide, largely because of Kano's ban, and this year's immunisation campaign is key to a global effort to eradicate polio worldwide by next year. --More 2204 Local Time 1904 GMT