WASHINGTON/CONAKRY - The United Nations said $600 million in supplies would be needed to fight West Africa's Ebola outbreak, as the death toll from the worst ever epidemic of the virus topped 1,900 and Guinea warned it had penetrated a new part of the country.The pace of the infection has accelerated, and there were close to 400 deaths in the past week, officials said on Wednesday. It was first detected deep in the forests of southeastern Guinea in March.The hemorrhagic fever has spread to Liberia, Sierra Leone, Guinea, Nigeria, and Senegal, and has killed more people than all outbreaks since Ebola was first uncovered in 1976. There are no approved Ebola vaccines or treatments.An experimental Ebola vaccine that Canada said it would give to the World Health Organization for use in Africa was as of Wednesday still in the lab that developed it as officials are puzzled over how to transport it.Ottawa said on Aug. 12 that it would donate between 800 and 1,000 doses of the vaccine, being held at Canada's National Microbiology Laboratory in Winnipeg."We are now working with the WHO to address complex regulatory, logistical and ethical issues so that the vaccine can be safely and ethically deployed as rapidly as possible," Health Canada spokesman Sean Upton said in a statement."For example, the logistics surrounding the safe delivery of the vaccine are complicated." Upton said one of the challenges was keeping the vaccine cool enough to remain potent.Human safety trials are due to begin this week on a vaccine from GlaxoSmithKline Plc and later this year on one from NewLink Genetics Corp.