BACKGROUND: What does it mean to be vulnerable in a pandemic? COVID-19 and its complex ramifications have challenged policymakers and researchers worldwide to redefine and reassess vulnerability. This paper presents experiences of being vulnerable during the pandemic among communities in Indonesia, Nepal and Vietnam. METHODS: From November 2020 to April 2021, we conducted qualitative research with communities in 13 locations including Jakarta, Bandung and Sumba in Indonesia; Morang & Sunsari, Kathmandu, Bhaktapur, Sindulpalchowk, Lower Mustang and Kapilvastu in Nepal; and Hanoi, Ho Chi Minh City, Nam Dinh and Dak Lak in Vietnam. We held discussions with key informants from local communities and healthcare systems to explore local ideas of vulnerability. Based on these discussions and findings from our media monitoring at all study locations, community members at high risk of adverse impacts from the pandemic were identified. Participants were purposively sampled to represent a range of age groups, occupations and levels of exposure to COVID-19 in the community and enrolled in semi-structured in-depth interviews about their experiences with the pandemic and public health responses. We analyzed and framed the results using Luna’s metaphor of “vulnerability layers”. RESULTS: In total we held discussions with 16 key informants from local communities and healthcare systems and collected 93 in-depth interviews with community participants. Using the “vulnerability layers” metaphor, we describe how stimulus conditions, namely stringent public health responses to COVID-19, may aggravate vulnerabilities a person already experiences or create new vulnerability experiences (for example, stigmatized status). A vulnerable experience can be exacerbated by the layering of multiple vulnerabilities or their cascade effects; on the other hand, it can be mediated by personal or collective protective factors. Our findings also demonstrate the role of context, including local disease control approaches and sociocultural attitudes and norms, in both the activation of and protection against vulnerability. CONCLUSIONS: Vulnerability assessments should take into account potential stimulus conditions (including public health responses) and local complexities rather than relying on groupings of impacted people. An understanding of the local context is also essential to improve the uptake and effectiveness of public health measures. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12910-026-01400-y.