Query: When had Nigeria not had a reported polio case in 6 months for the first time?
Context: Nigeria was the only country in Africa to have never eradicated polio, which it periodically exported to other African countries; Polio was cut 98% between 2009 and 2010. However, a major breakthrough came in December 2014, when it was reported that Nigeria hadn't recorded a polio case in 6 months, and on its way to be declared Polio free. In 2012, a new bone marrow donor program was launched by the University of Nigeria to help people with leukaemia, lymphoma, or sickle cell disease to find a compatible donor for a life-saving bone marrow transplant, which cures them of their conditions.