Authorities in northern Nigeria’s Kano State said on Sunday the suspension of polio immunisation in the state would remain in force until their fears about the vaccines used were adequately addressed. Reacting to a declaration signed on Thursday by Nigeria’s Minister of Health Eyitayo Lambo, pledging to immunise all Nigerian children against polio, Kano State spokesman Sule Yau Sule said vaccination could only resume in the state when authorities were convinced that the vaccines were safe. Kano State was among three northern states that halted polio immunisation in October following allegations by Islamic leaders that the vaccine to be administered to thousands of children was contaminated with HIV and anti-fertility agents.