Ebola clinical trials: Five lessons learned and a way forward.

Background Little progress was made in advancing Ebola-specific therapies during the epidemic that began in West Africa in late 2013. Throughout the last quarter of 2014, which saw the greatest numbers of cases, only a handful of clinical trials were underway. Subsequently, as incident cases dwindled, the number of clinical trials increased dramatically, but few, were destined to recruit to their accrual targets. The predictable barriers to implementing clinical trials in resource-constrained settings are compounded by unique characteristics of Ebola — including its high fatality rate, its swift transmission through populations, and the grave risks for exposed health care workers.