Two Liberian healthcare workers who received experimental medication to fight the Ebola virus have shown some improvement, the
In a statement, the international health agency said that doctors working in Liberia told them a doctor and nurse have shown "marked improvement" after receiving the experimental treatment ZMapp.
A second doctor being treated with the drug in Liberia remained in serious condition, the statement said, but "has improved somewhat."
It's not clear whether ZMapp is effective or even harmful. The survival rate for patients infected with Ebola in the current outbreak stands at about 50%.
According to the Associated Press, the three healthcare workers received the last known doses of ZMapp, and were the first Africans to receive the experimental medication, which had never been used in humans.
The medicine was also previously used to treat two Americans working with Ebola patients in Liberia, who were later evacuated to Emory Hospital in Atlanta.
Both are now Ebola-free, the hospital announced Thursday. One was released Tuesday, and the other left the hospital Thursday.
Another patient who received ZMapp, a Spanish priest, later died after being evacuated to his home country.
The medication, made by Kentucky BioProcessing for San Diego-based Mapp Biopharmaceutical, was in extremely short supply, but the Liberian government was able to obtain three doses.
The manufacturer said on Aug. 12 that all supplies of the treatment had been exhausted, and that it will take months to produce more. The company has said it is working on accelerating production.
The use of ZMapp raised major ethical questions regarding experimental drugs in serious disease outbreaks. A WHO panel recently declared that the use of experimental treatments for Ebola patients in West Africa is ethical, adding that five such treatments were being considered for "compassionate use."