In 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a rapidly emerging virus causing the coronavirus disease 2019 (COVID-19) pandemic, had no known effective prophylaxis and no widely available proven effective antiviral treatment. Hydroxychloroquine/Chloroquine was identified as an early potential therapeutic candidate drawing on evidence from reports of both in vitro and in vivo testing. A multicountry placebo-controlled randomized trial was set to evaluate the use of hydroxychloroquine/chloroquine to prevent infection in healthcare workers and staff working in a health facility involved in COVID-19 management. One of the sites of this trial was in Niger. In Niger, of the 240 persons who were provided information about the study and with whom participation was discussed, only five participants provided their informed consent. In this article, we describe the key difficulties encountered in the conduct of this trial from the perspective of the site study team. Among the difficulties, we recognize that the epidemic context, controversy surrounding hydroxychloroquine, vaccine rollout, participants' perspectives, and trial design had a major impact on participation.