Kent Brantly, who contracted the deadly Ebola virus and survived, smiles during a news  conference at Emory University Hospital in Atlanta on Aug. 21. (Tami Chappell/Reuters)

Kent Brantly, the American doctor who survived the Ebola virus, has donated a unit of his blood to another American being treated for the virus in Nebraska.

The donation, which was first reported by NBC News, was confirmed by a spokesperson for Samaritan's Purse, the aid organization Brantly was associated with while he worked as a medical missionary in Liberia.

"He flew out from North Carolina to Nebraska to give a unit of blood," Franklin Graham president and CEO Samaritan's Purse told NBC News. "His blood was a perfect match."

Brantly flew to Omaha on  Sept. 5 to donate a unit of his blood to 51-year-old doctor Rick Sacra, who is the same blood type, the spokesman told The Post.

Sacra, who is being treated at Nebraska Medical Center, was the third of four Americans known to have been flown from a West African nation to the U.S. after being infected with Ebola. A fourth American with Ebola is being treated at Emory University Hospital in Atlanta, where Brantly and another missionary, Nancy Writebol, were successfully treated for the virus.

As a survivor, Brantly is immune to this particular strain of Ebola. The blood of survivors is believed to contain antibodies that can help sick people fight the disease.

Brantly himself received a unit of blood from a young Ebola survivor he'd treated in Liberia before he  was flown back to the United States while battling his own sickness.

Earlier this month, the World Health Organization said the use of survivors' blood to battle the epidemic in West Africa is a "matter of priority."

“We agreed that whole-blood therapies and convalescent serum may be used to treat Ebola virus disease and that all efforts must be invested into helping affected countries use them safely,” Marie-Paule Kieny, assistant director general for health systems and innovation at the WHO told reporters.

The virus has infected more than 3,600 people in Guinea, Liberia, Sierra Leone, Nigeria and Senegal. According to the WHO, 47 percent of those infected during the outbreak have survived. The large pool of survivors and the lack of specific and proven treatment or vaccine for the virus makes the blood of survivors one of the most important treatments available right now.

Sacra, a medical doctor, was delivering babies in a Liberian hospital when he became sick. He was not treating Ebola patients so it is unclear how he became infected.

Doctors at Nebraska Medical Center say he is in stable condition at the hospital.