ATLANTA—Kent Brantly and Nancy Writebol have recovered. The two American aid workers, who since early August had been receiving treatment for Ebola at Emory University Hospital, are being released—hospital officials in Atlanta cited multiple clean blood tests for both. Standing in front of a press conference this morning, Brantly simply said “I am thrilled to be alive.”

Holding his wife’s hand, Brantly left Emory University Hospital to a round of applause and long hugs from 20 doctors and nurses who cared for him during the past 19 days; Writebol left quietly two days ago. The virus typically has a case fatality rate of 60 to 90 percent in hospital settings in Africa.

“After a rigorous course of treatment and thorough testing, we have determined, in conjunction with the Centers for Disease Control, that Dr. Brantly has recovered and can return to his family, his community and his life without public health concerns,” said Bruce Ribner, who led the five-doctor, 21-nurse team that cared for both patients. The two will return to Emory for follow-up appointments in coming months.

Ribner emphasized that both patients are not contagious and now have immunity to the Zaire strain of the Ebola virus. They will not relapse and are not carriers for Ebola. Though some World Health Organization documents suggest semen can carry the virus for months after infection, Ribner repeated three times that he and other researchers see no epidemiological evidence that Brantly needs to worry.

“The limited knowledge of Ebola has created understandable anxiety,” Ribner said. “I understand there are a lot of questions and concerns regarding Ebola. We cannot let our fears dictate our actions.”

Brantly and Writebol, who contracted Ebola in Liberia in late July, are the first patients treated for the virus on American soil. Ebola spreads through bodily fluids, such as blood, vomit and diarrhea, but nobody knows exactly how Brantly and Writebol contracted the virus. During his speech, Brantly credited the experimental monoclonal antibody drug ZMapp as one factor in his recovery, but wouldn’t say wether it was ZMapp, transfusions from a 14-year-old patient Brantley treated in Liberia, or other specific treatments that allowed his patients’ recovery. Writebol and three healthcare workers in Liberia (who seem to be recovering) also took ZMapp, but so did a Spanish priest who subsequently died.

“We just have no idea,” Ribner said, but added the high level of ICU-type care Brantly and Writebol received was the main reason they recovered.

The Emory care team now plans to compile observations and submit papers to journals. They also want to update CDC and WHO guidelines regarding treatment of Ebola to help doctors in West Africa better offer supportive care—particularly the replenishment of electrolytes lost to dehydration. “Our work is far from over,” Ribner said. “We’re mindful of those in West Africa still fighting for their lives against this threat and those caring for them.”

The death toll in West Africa now stands at 1,350. Nearly 2,500 people are sick. Earlier today, the Wellcome Trust and the United Kingdom’s Department for International Development issued a research “all call” to find a drug to help the outbreak. The UK agency is putting up $10.8 million to fund research, and Wellcome Trust is adding another $66.5 million to help researchers in Africa.

“Encourage those in positions of leadership and influence to do everything possible to bring this Ebola outbreak to an end,” Brantly said before he left Emory. Now the real work starts.