The fight against Ebola in Liberia got some welcome news -- with a little caution . The number of new cases in the nation appears to be declining , with fewer burials , plateauing lab confirmations and less-cramped hospitals , the World Health Organization said . If the trend continues , the hardest hit nation will get a much-needed break . The deadly virus has left at least 4,922 people dead mostly in Guinea , Sierra Leone and Liberia . More than half of the deaths have been in Liberia , which has buckled under the weight of the epidemic , and even declared a shortage of body bags this month . Too soon to celebrate . Though health experts expressed optimism , they warned that the latest observation does not mean Ebola is under control in Liberia . The virus has the potential to appear in waves , which can be mistaken for declining cases . `` The danger now is that we move , instead of a steady downward trend that gets us down to zero , that we end up with a oscillating pattern where the disease starts going up and down and areas start getting re-infected , '' said Dr. Bruce Aylward , an assistant director-general at the WHO . `` What gets the heat out of this thing and slows it down is n't necessarily what is going to get us to zero . '' The numbers have been on the decline for about week , he said . Not declining in Sierra Leone . Despite the good news in Liberia , Ebola infections have not slowed down in Sierra Leone , he said . One of the goals is to educate the population to help reduce contact between Ebola patients and those who are not infected . `` With the concerted community engagement , with safe burials , with a big push on getting the right information out through the right channels , you can rapidly get the behavior changes that are critical to protecting populations , '' Aylward said at a news conference in Geneva on Wednesday . `` And that can translate into positive trends in terms of the disease . '' Scramble to develop vaccines . As the world reels from the outbreak , health experts are fast-tracking tests for various vaccines , and hope to have millions of experimental doses by next year . There is currently no cure or vaccine for Ebola , which has infected nearly 14,000 people mostly in the three most affected nations . Scientists racing to stop the epidemic are trying various experimental drugs on patients , including ZMapp and TKM-Ebola . In addition to drug development , there 's a scramble to develop vaccines , with scores of companies working on experimental doses . Health care workers in affected nations will get the first opportunity to try the experimental vaccines . At least 521 health workers have caught the virus worldwide . Of those , 272 have died . Ebola is spread by direct contact with the bodily fluids of an infected person . Complete coverage on Ebola .
Is Liberia getting a much-needed break ? The Ebola outbreak in West Africa has killed more than 11,300 people and infected nearly 11,000 since it began last March. There is currently no cure or vaccine for Ebola .