CONCLUSION
deaths
There are many aspects that may explain low participation in the COPCOV study in Niger. First, Niger had a very low number of confirmed cases and deaths due to COVID-19, so it was not perceived as a priority problem. Second, the availability of vaccines with proven efficacy and no need for repeated daily doses may have been perceived as being in direct competition with the use of the investigational product. Third, controversies about HCQ were widely publicized, leading to the development of negative opinions by participants about its effectiveness. Fourth, because participants were healthcare professionals, they belonged to a medical community that may have been more likely to develop specific opinions and beliefs around a particular health topic, which may even have been at odds with the investigator’s perspective, and to resist the study team’s communication efforts. Many of these issues affected all sites in the study, which were able to recruit 4,652 participants in 25 sites in 11 countries, the majority of them in Africa (including Benin, Côte d’Ivoire, and Mali), although this total was substantially less than the planned number. This confirms that the conduct of clinical research to find a curative or preventive solution to an ongoing global pandemic was subject to context-specific issues, such as the emergence of alternative products, parallel and competing public health interventions, and public perceptions, whose complex interplay may have led to the study’s success or failure in a particular site. Although adaptive platform trials may hold promise for treatment, the challenges for prophylaxis are numerous.