analysis (SMA). Our process was iterative as the data collection and data analysis were deepened until all categories of stakeholders have been identified, their positions and relationships mapped and their motivations and barriers explored (Varvasovszky and Brugha 2000). Participatory approaches helped to reduce communication barriers and stimulate discussion onparticularly sensitive topics (Bordier et al. 2018). This approach has already been applied to ABR surveillance programs in Vietnam (Bordier et al. 2018) and the antibiotic value chain in Laos (Poupaud et al. 2021). By exploring barriers to the implementation of new regulations using a participatory approach, we identified systemic lock-ins (economical, political, technical, and social) to reducing antibiotic usage in chicken production in Vietnam (Baudoin, Hogeveen, and Wauters 2021). However, we recognize that our study has some limitations. To begin, almost all of the interviews were conducted online due to the health crisis. This format present a great interest in term of time and budget and no significant difference in thematic content (length of the interviews, numberofwords, numberofcodes generated) with in-person interviews have been shown (Krouwel, Jolly, and Greenfield 2019; Namey et al. 2020). However, we have identified several biases that could have hampered our study. Direct observations are reduced, and some information is lost (lack of informal discussions, misunderstandings, longer time to build trust, and more complicated debriefing with the team). Another limitation may have been the sensitivity of the subject to the participants. Indeed, these regulations are already enforced or will be soon, and participants might have been worried about the consequences of expressing their true opinions. Weattempted to reduce this bias by interviewing several respondents from the same category and gathering information from the perspective of other participants. However,wefailedtocontactinformal stakeholderswhocouldhavehelpedusfurtherdescribe the informal value chain. Due to time and technical constraints, we only interviewed one representative for some categories of stakeholders. Thus, it might have been relevant to interview another veterinarian district station to clarify their role in the drug value chain. The identification of stakeholders was also driven by the knowledge and experience of the Vietnamese context of the authors. However, the iterative process allowed us to go beyond this limit as new participants were recruited based on the participant's knowledge. Finally, translation might also have caused misunderstandings. We are also aware that the representation of the veterinary drug value chain may be incomplete, as it is based on stakeholder interviews and reflects the situation at the time of data collection in 2021. We can however assume that at the time of publication, the results will not be significantly different because as the participants pointed out, human behaviors and policies or regulations are not easy to change in the short term. Theinclusionorexclusionof somecategoriesof stakeholdersmayinfluencetheconclusions drawn and introduce bias because of their different perspectives on the regulations. Small- scale farmershavebeenblamedforantibioticmisuse andlowregulatory compliance.However, our sample lacked small farmers compared to other stakeholders, and wedid not capture their perspectives on their role in ABR as identified by other stakeholders. Thus, additional research is needed to investigate farmers' perceptions about the ABUreduction and to identify howthey adapt to the need for changing practices.