(CNN) -- The first two doses of an experimental serum created to treat Ebola went to American missionaries. Then the drug was sent to treat a Spanish priest. The two Americans, Dr. Kent Brantly and Nancy Writebol, appear to be recovering. The priest, Miguel Pajares, died Tuesday morning. That's the problem with experimental drugs that have never been clinically tested in humans: No one knows whether they'll work -- and if they do, in whom. This week, the World Health Organization gathered a group of ethicists to decide whether unproven medications and vaccines should be used in the current Ebola outbreak. As the death toll from the epidemic soared over 1,000, the WHO panel unanimously concluded that it is ethical to offer medications to fight the Ebola virus, even if their effectiveness or adverse effects are unknown.
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NEW: Canada to offer WHO up to 1,000 doses of experimental Ebola vaccine
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WHO panel: It is ethical to offer unproven medication to try to fight Ebola
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Pair who took an experimental drug appear to be improving, but one man who took it died
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Sample doses of the experimental drug ZMapp are on their way to Liberia
As with @placeholder, other questions include how and on whom it should be used.