I can't think of too many people better qualified to break down the ethics of fighting Ebola than Peter Singer.

In this respect, Ebola is – or, rather, was – an example of what is sometimes referred to as the 90/10 rule: 90% of medical research is directed toward illnesses that comprise only 10% of the global burden of disease. The world has known about the deadly nature of the Ebola virus since 1976; but, because its victims were poor, pharmaceutical companies had no incentive to develop a vaccine. Indeed, pharmaceutical companies could expect to earn more from a cure for male baldness.

Government research funds in affluent countries are also disproportionately targeted toward the diseases that kill these countries’ citizens, rather than toward diseases like malaria and diarrhea that are responsible for much greater loss of life.

The most accurate way to judge the efficacy of a vaccine is through a double blind trial. One group of patients suffering from the malady are given the potential vaccine, the other set a placebo, and neither the doctors nor patients know who received what. When dealing with a shortage of vaccines and a disease as deadly as Ebola, the usual rules may not apply. That may be okay.

But, when facing a disease that kills up to 70% of those who are infected, and no accepted treatment yet exists, patients could reasonably refuse consent to a trial in which they might receive a placebo, rather than an experimental treatment that offers some hope of recovery. In such cases, it might be more ethical to monitor carefully the outcomes of different treatment centers now, before experimental treatments become available, and then compare these outcomes with those achieved by the same centers after experimental treatments are introduced. Unlike in a randomized trial, no one would receive a placebo, and it should still be possible to detect which treatments are effective.