Abstract
In 2004, the first ever multi‐sited clinical trials studied the prospect of HIV biomedical prevention (referred to as pre‐exposure prophylaxis—‘PrEP’). The trials were implemented at several international sites, but many officially closed down before they completed. At most sites, both scientists and community AIDS advocates raised concerns over the ethics and scientific rationales of the trial. Focusing on the Nigerian trial site, we detail the controversy that emerged among mostly Nigerian research scientists who scrutinized the research design and protocol. While some of the disputes, especially those pertaining to community engagement mechanisms, were ultimately resolved in international fora and implemented in later PrEP trials, concerns over science rationales and assumptions were never addressed. We argue that scientific rationales should be treated as ethical concerns and suggest that such concerns should be deliberated at host sites before the trial protocol is finalized.