We first organized a focus group discussion (FGD) in December 2020 in Hanoi with 12 stakeholders from the antibiotics and alternative feed additives value chain belonging to different categories. Four participants were from the public sector (three from the Sub- Department of Animal Health and Livestock Production (Sub-DAHLP) and one from the veterinarian district station), while eight were from the private sector. The different categories of stakeholders were identified through semi-structured interviews in a preliminary study (Bâtie et al. 2022). The participants were invited based on the list of contacts of one researcher of the team. The objectives were to collectively map the antibiotics and alternative feed additives value chainandidentify key stakeholders.The discussion wasorganizedaroundthree topics: (i) identifying the stakeholders in the chain and their roles, (ii) drawing the chain and their interactions, and (iii) identifying existing antibiotic-related legislation [Supplementary Material 1]. The four researchers from VNUA led the three-hour in-person focus group in Vietnamese, using participatory epidemiology tools such as flowchart building (Catley, Alders, and Wood2012).The first author waspresent remotely and received simultaneous Vietnamese English translation from a team member. The FGD was recorded, the minutes were transcribed and translated into English, and the value chain drawn by the participant was translated and copied into a Word document. From March to October 2021, we conducted semi-structured interviews in northern and southern Vietnam with representatives of the categories of stakeholders identified during the FGD. From March to October 2021, 39 interviews were conducted with participants from four provinces (Hanoi, Hung Yen, Hai Phuong, and Bac Ninh) in north Vietnam and three provinces (Hô Chi Minh, Long An, and Dong Thap) in south Vietnam. Participants included government officials (n = 12), private sector workers (n = 18), and foreign partner institutions (n = 4). Table 1 describes the participants. Participants were invited based on the list of contacts of the research team and through an iterative process. Indeed, new categories of stakeholders were added as we deepen our analysis and that new elements have emerged from the semi- structured interviews (Reed et al. 2009). The interview guide was divided into four main topics: (i) position and role within the antibiotics and alternative feed additives value chain, (ii) interactions with other stakeholders and the nature of those interactions, (iii) knowledge and opinions on antibiotic resistance in Vietnam and about the NAP, and (iv) barriers and motivations for implementing the twonewregulations under consideration and their expected impacts on the chain [Supplementary Material 2]. Because of the COVID-19 health crisis, five interviews were conducted in person, some were conducted half in person and half online and other fully online. During the interview, a map of the veterinary drug value chain was shared with the participant. Thefirst version of the mappresentedwasbuiltfrom the results of the FGD andthenmodifiedastheinterviewsprogressed.Participantswereasked to identify themselves on the map and to describe the nature of their interactions with the other stakeholders. They were able to propose changes to the map. The interviews were audio-recorded and lasted between 60 to 90 minutes. The first author conducted them in English or French, with the research assistant translating into Vietnamese when necessary. Throughout the interviews, notes were taken. Depending on the interviews, field notes were transcribed and translated in English and were expanded with audio recording of the discussion in Vietnamese and