Washington, Muharram 12, 1436, Nov 5, 2014, SPA -- Scientists across the United States say they cannot obtain samples of Ebola, complicating efforts to understand how the virus is mutating and develop new drugs, vaccines, and diagnostics. The problems reflect growing caution by regulators and transport companies about handling Ebola as well as the limited resources of West African countries struggling to help thousands of infected citizens. Ten scientists from eight major research institutions contacted by Reuters reported they were unable to obtain Ebola samples in recent months. Tulane University, one of the institutions, received samples this week, and the U.S. Centers for Disease Control and Prevention (CDC) said it has reached a deal to get live specimens, but it is unclear if new supplies will satisfy demand, and transport remains challenging. Scientists also say Liberia, Sierra Leone, and Guinea have been slow to release samples as they fight to contain the worst Ebola outbreak on record. Ebola mutates as it spreads, and while few expect it to acquire the ability to transmit through air, for instance, scientists require a constant supply of fresh samples to track such changes. The delay in obtaining samples is not likely to postpone the development of experimental treatments, but if the virus undergoes significant changes that go undetected, the drugs and tests might not work, researchers said. --SPA 17:39 LOCAL TIME 14:39 GMT www.spa.gov.sa/w