More than $430 million will be needed to bring the worst Ebola outbreak on record under control, according to a draft document laying out the World Health Organization's battle strategy.

The plan sets a goal of reversing the trend in new cases within two months, and stopping all transmission in six to nine months. It requires funding by governments, development banks, the private sector and in-kind contributions, according to the document obtained by Bloomberg News.

The current outbreak, which has killed 1,427 people in Liberia, Guinea, Sierra Leone and Nigeria, may soon exceed all previous Ebola outbreaks combined. The sum now being sought is six times more than the $71 million the WHO suggested was needed in a plan published less than a month ago.