( CNN ) -- The Bill and Melinda Gates Foundation announced Wednesday it will donate $ 50 million to help fight the Ebola outbreak in West Africa . More than 2,200 people have died in Guinea , Liberia and Sierra Leone , where the outbreak has been concentrated . Cases have also been reported in nearby Nigeria and Senegal . The foundation says the money will be used to enable international aid organizations and national governments `` to purchase badly needed supplies and scale up emergency operations in affected countries . '' It will also `` work with public and private sector partners to accelerate the development of therapies , vaccines , and diagnostics that could be effective in treating patients and preventing further transmission of the disease . '' The first human trial of an experimental Ebola vaccine began last week at the National Institutes of Health . This is considered the deadliest Ebola outbreak in history . The World Health Organization said Monday the rapid spread of the virus in Liberia shows no sign of slowing . `` The number of new cases is increasing exponentially , '' WHO said , calling the situation a `` dire emergency with ... unprecedented dimensions of human suffering . '' Taxis packed with families who fear they 've contracted the deadly virus criss-cross the Liberian capital , searching for a place where they can be treated , WHO said . But there are no available beds . `` As soon as a new Ebola treatment facility is opened , it immediately fills to overflowing with patients , '' the U.N. group said . To help ease some of the burden on West Africa 's already over-taxed medical system , the United States announced Tuesday it will send $ 10 million in additional funds . That 's in addition to the $ 100 million Washington has already sent to help fight the outbreak . USAID also announced it will make $ 75 million in extra funds available . The new funds will pay for transportation and support to send 100 more health care workers to help fight the epidemic . The WHO and several nonprofit agencies on the ground have repeatedly called for the international community to send additional trained help . USAID funding has already provided 130,000 sets of personal protective equipment , 50,000 hygiene kits , and 1,000 new beds . USAID has created a website where trained nurses , physician assistants or doctors who want to help can sign up . On Sunday , President Barack Obama said the Ebola outbreak needs to be a `` national security priority . '' Obama told NBC 's `` Meet the Press '' that the U.S. military could help set up isolation units and provide security for public health workers . `` If we do n't make that effort now , and this spreads not just through Africa but other parts of the world , there 's the prospect then that the virus mutates . It becomes more easily transmittable . And then it could be a serious danger to the United States , '' he said . U.S. 'ill-prepared ' for a pandemic , feds say . CNN 's Betsy Klein contributed to this story .
Bill and Melinda Gates Foundation joins fight of Ebola outbreak in West Africa . More than 2,200 people have died in Guinea , Liberia and Sierra Leone . Money will be used to purchase supplies and scale up emergency operations .