In crafting our paper on addressing the ethical challenges in HIV prevention research with people who inject drugs,1 we had hoped to stimulate further discussion and deliberation about the topic. We are pleased that three commentaries on our paper have begun this process.2 3 4 The commentaries rightly bring up important issues relating to community engagement and problems in translating research into practice in the fraught environments in which PWID face multiple risks. These risks include acquisition of HIV as well (...) as criminalisation, stigma and lack of access to needed healthcare, prevention and social services. We take this opportunity to respond to the excellent points raised by the commentators. All of the commentaries support our emphasis on robust community engagement with PWID and other stakeholders in designing and conducting HIV prevention research, but urge us to go farther. Wolfe highlights the difficulty of even engaging with community members in oppressive settings, where authorities severely restrict civil liberties of PWID so that even discussing issues related to drug use and enforcement may place individuals at risk. To overcome such limitations, he appropriately suggests interviewing confidentially those who have previously been detained in closed settings as part of the community engagement process. Similarly, Wolfe observes that critical issues can be overlooked with a narrow focus on study procedures if contextual factors before, during or after a study are ignored. For example, he cites the risk of overdose for study participants who have been abstinent during a study and subsequently resume injecting when the study concludes. These kinds of risks may not be obvious …. (shrink)