The U.N. Ebola chief says it's going to take several more months before the outbreak in West Africa is under control.
In September, the World Health Organization said it wanted to have 100 percent of Ebola cases isolated by Jan. 1. It conceded earlier this month that it didn't fully meet an interim target -- but it hasn't made clear what that means for the Jan. 1 goal, which some have said now looks unrealistic.
Dr. David Nabarro said there has been "a massive shift" over the last four months in the way governments have taken the lead in responding to the epidemic and communities are taking action.
But he said Thursday that greater efforts are still needed to control Ebola in hard-hit Sierra Leone, Liberia and Guinea.