ZMapp, the untested Ebola drug, arrived in the West African country late Wednesday. Assistant Health Minister Tolbert Nyenswah said three or four people would begin getting it Thursday, although another health official said there was only enough for three people.
The government had previously said two doctors would receive the treatment, but it was unclear who else would.
These are the last known doses of ZMapp left. The San Diego-based company that developed it has said it will take months to build up even a modest supply.
The Ebola outbreak was first identified in March in Guinea and has since spread to Liberia, Sierra Leone and Nigeria, killing more than 1,060 of the 1,975 people sickened by it, according to the World Health Organization.
The outbreak has overwhelmed the already strained health systems in West Africa and raised questions about whether authorities are doing enough to respond.
On Thursday, police in riot gear dispersed an angry crowd in the Liberian capital of Monrovia who were protesting that an Ebola victim's body had not been taken away by health workers.
The outbreak has also sparked an international debate over the ethics of giving drugs that have not yet been tested to the sick and deciding who should get the drugs. So far, only two Americans and one Spaniard have received ZMapp. The Americans are improving — but it is unclear what role the drug has played. The Spaniard died within days.
Doctors Without Borders, which is running many of the Ebola treatment centers and whose staff have tussled with whether to provide ZMapp, said such choices present "an impossible dilemma."
Now Liberian officials are facing those questions.
"The criteria of selection is difficult, but it is going to be done," said Dr. Moses Massaquoi, who helped Liberia obtain the drug from Mapp Biopharmaceutical. "We are going to look at how critical people are. We are definitely going to be focusing on medical staff."
He added people who were past the "critical phase" and looked likely to survive would not be chosen.
In this outbreak, over 50 percent of those sickened with Ebola have died, according to the U.N. health agency.
Massaquoi said there was only enough of the drug to treat three people. Treatment will be staggered, so doctors can observe the effects in one patient before moving on to the next. It was not clear yet if the treatment had started.
The confusion over how many people could be treated may stem from the fact that doctors don't know the best dose to try since the drug has never been tested in humans.
Arthur Caplan, director of medical ethics at NYU Langone Medical Center, said the choice of who to treat would have to balance helping the largest number of people with learning the most from the treatments.
He said the question is not "whose life do we save?" but "who gets the chance to be experimented on?"
For that reason, recipients need to be good experimental subjects — people who have recently contracted the disease and are more likely to respond to treatment or perhaps younger patients, he said. In order to study the long-term effects, doctors will likely prefer people who can be observed for months, which might eliminate people living in remote places, he added.
Nigeria announced Thursday that one more person has been infected with Ebola, bringing the country's number of cases to 11. Health Minister Onyebuchi Chukwu said the latest patient is a doctor who helped treat the country's first Ebola case, Liberian-American Patrick Sawyer who flew in last month and died July 25.
All Nigerians who contracted the killer virus have had direct contact with Sawyer.
DiLorenzo reported from Dakar, Senegal. Wade Williams and Abbas Dulleh in Monrovia, Liberia, and Bashir Adigun in Abuja, Nigeria contributed to this report.
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