A Spanish priest sickened by ebola in Liberia has received the third-ever dose of an experimental ebola drug made in the U.S., but no Africans have received the drug, raising ethical questions, WashingtonPost reports.

Two Americans evacuated from Liberia to the U.S. have been improving at Atlanta’s Emory University Hospital after getting ZMapp, an experimental ebola drug developed by San Diego-based Mapp Biopharmaceutical and manufactured by Kentucky-based BioProcessing. A Spaniard was treated in Spain over the weekend.

ZMapp has not been approved by the U.S. Food & Drug Administration. It is so new and unproven that very little of it is available and its effectiveness is unknown, according to WashingtonPost. It could end up doing more harm than good. Producing small amounts of the drug will take months, and even then, using it more widely would present other ethical dilemmas, the report said.

Companies can provide experimental drugs on a compassionate-use basis, but usually after they have been fully tested. In the U.S., this use must be approved by the FDA, but the FDA has no authority overseas. It is up to the company whether it wants to share its drug.

Many Africans find it hard to accept that two Americans and a Spaniard were able to get the treatment after being infected in West Africa, but no African has been treated with the drug.

“There’s no reason to try this medicine on sick white people and to ignore blacks,” said Marcel Guilavogui, a pharmacist in Conakry, Guinea. “We understand that it’s a drug that’s being tested for the first time and that could have negative side effects. But we have to try it in blacks too.”

The ethical questions posed by the existence of this experimental drug have been so challenging that the U.N. health agency organized a teleconference Monday of about 12 infectious disease experts, ethicists and patient representatives, including people from universities and the Doctors Without Borders. Uganda and Senegal had people in the meeting, but most of the participants were from developed countries.

The World Health Organization said it plans to hold a news conference Tuesday, but didn’t say if it would make recommendations for which ebola patients should get experimental therapies, and how.

Art Caplan is director of bioethics at New York University Langone Medical Center. He did not participate in the WHO teleconference but said the drugmaker should make its policy clear for distributing its treatment. “I don’t think this scarce resource should just be given to whoever is best connected,” Caplan said.