Two American citizens who were flown out of Liberia after being infected with Ebola virus have recovered and have been discharged from the hospital. Ms. Writebol was discharged on Tuesday, August 19 while Dr. Kent Brantly was discharged today, August 21 by authorities of Emory University Hospital, CNN reports. Speaking at a news conference in Atlanta with Emory University Hospital staff members, Dr. Kent expresses joy to be alive, well and reunited with his family. For Brantly to leave isolation, two blood tests done in a two-day period had to come back negative. According to Dr. Bruce Ribner, director of Emory’s Infectious Disease Unit, their discharge poses no public health threat, adding that what they learned in caring for them will help advance the world’s understanding of how to treat Ebola infections and also improve survival rate in other parts of the world. He added that there is strong epidemiological evidence that after an Ebola patient survives the disease, the survivor becomes immune to that particular strain of Ebola. The two Americans were infected with Ebola while working with the aid organization Samaritan’s Purse in Liberia and they were both evacuated in August, in a plane specially equipped with an isolation tent, and accompanied by medical staff outfitted in head-to-foot protective clothing. They were taken to an isolation unit at Emory. Before they were evacuated from Liberia, they were both given experimental serum called ZMapp . There were reports that the experimental serum had been sent to Liberia to help in the fight against Ebola virus. Meanwhile, the Lagos state Government has reportedly halted the use of Canadian-made experimental vaccine, Nano Silver, insisting that only US-made ZMapp drug will be allowed for treating Ebola infected patients.