“We depend on the body’s defenses to control the virus,” he said. “We just have to keep the patient alive long enough in order for the body to control this infection.”

Dr. Ribner said Emory would have a robust roster of medical workers handling the care of Dr. Brantly and Ms. Writebol, including four infectious disease doctors, a rotating cast of nurses and, as needed, subspecialists.

Dr. Alexander P. Isakov, the executive director of Emory’s Office of Critical Event Preparedness and Response, said in an interview that the staff in the containment unit had volunteered to work there, and that some members who were supposed to be on vacation had offered to cancel their plans to take care of the new patients.

Image Dr. Bruce S. Ribner Credit... Jessica Mcgowan/Getty Images

Dr. Brantly and Ms. Writebol will be housed in a unit that is small and positioned well away from other patients at the hospital. They will probably have limited contact with visitors, Dr. Ribner said, communicating with nonmedical personnel through telephones and an intercom system. A sheet of glass will separate the ill from the healthy.

Dr. Isakov said the unit had been used only three to five times since it was built; all of the patients were suspected of having serious diseases like SARS, but turned out not to have those illnesses. This is the first time the unit will house patients who are truly infected with a dangerous disease.

Dr. Ribner said, “We have far more training exercises than we do activations because of patients with these pathogens.”