Trials for an Ebola vaccine in West Africa could start as early as December, the World Health Organization said Friday. It also announced that if successful, hundreds of thousands of doses could be distributed by mid-2015. The announcement came after closed-door talks with medical experts at the United Nations on Thursday. The two leading vaccine candidates are rVSV from Canada and ChAd3, which is made by GlaxoSmithKline. There are an additional five more potential vaccines in the pipeline.