Dr. Kent Brantly, 33, was evacuated to the U.S. after contracting Ebola while treating infected patients in Monrovia, Liberia. Brantly and a second American, Nancy Writebol, were both working with in a clinic for Ebola patients in Liberia, when they were infected with the deadly virus last month.

Brantly was described today as “improving,” by the Samaritan’s Purse, the aid group Brantly worked for in Africa.

Athough Brantly was given an unknown serum, there is no known cure for Ebola and to treat patients doctors have focused on providing supportive care by stabilizing a patient’s blood pressure, respiration and other vital signs.