One walked into the hospital... The other was taken on a stretcher... But both U.S. aid workers stricken with the deadly Ebola virus are now said to be improving. That may be because Dr. Kent Brantly and missionary Nancy Writebol each received an experimental drug for Ebola. It's called ZMapp and it's only been tested on monkeys until now. They're in the same isoaltion ward at Emory Univeristy Hospital in Atlanta.