Final answer:
Merck's donation of treatments for river blindness is an example of compassionate use, similar to the use of the experimental drug ZMapp during the Ebola outbreak in 2014, which was ethical according to a WHO panel.
Step-by-step explanation:
Merck's decision to donate more than one billion treatments to help end river blindness free of charge was an act of compassionate use. This term refers to the provision of experimental drugs to patients outside of clinical trials, typically in cases where there are no other treatment options and the patient is facing a serious or immediately life-threatening condition. The situation with ZMapp during the Ebola outbreak in 2014 provides an illustrative example. Despite ZMapp not being registered and having only been tested in monkeys, it was administered to infected individuals under the compassionate use ethical framework. The World Health Organization (WHO) convened a panel which concluded that offering such unregistered drugs could be ethical due to the high fatality rate associated with Ebola and the lack of alternative treatments.