The New York doctor received a plasma transfusion from the second American Ebola patient, Nancy Writebol, on Oct. 25th and underwent plasma and antiviral therapies while being treated.
New York mayor Bill de Blasio called Spencer a hero for volunteering to treat Ebola patients in Guinea, where he contracted the virus.
"He's a guy who went toward danger, went to where the need was greatest in the whole world. He suffered a lot these past few weeks but he's come back really strong."
Dr. Spencer is the last Ebola patient to have had the virus in the U.S. He was the first to be diagnosed in New York.