Geneva- The death toll from the Ebola virus outbreak worldwide has risen to 4,447, with the large majority of victims in West Africa, the World Health Organization (WHO) says today.

WHO Assistant Director General Bruce Aylward also said there could be up to 10,000 new cases a week within two months if efforts were not stepped up, but the rate of new infections in some areas has slowed down, he added. Sierra Leone, Liberia and Guinea are hardest hit by the outbreak. The progress towards an Ebola vaccine - in 80 seconds, there have been 8,914 cases overall, including fatalties, and the WHO says it expects this number to top 9,000 by the end of the week.

The WHO estimates its figures by taking the numbers of confirmed cases and multiplying them - from Guinea by 1.5, from Sierra Leone by 2 and from Liberia by 2.5 - to account for under-reporting.