This special issue of Anthropology in Action presents a collection of articles that refect on and analyse the role of social science in epidemic response. The COVID-19 pandemic has exposed deep social and economic inequalities within and across countries which produce unequal COVID-19 outcomes. Researchers have long noted the connections between socio- economic inequalities and infections, and there is growing recognition that epidemics are also social and political events (Bardosh et al. 2020). Anthropological and other social science research has contributed to epidemic response, through atention to cultural and politico-economic context, reframing community ‘resistance’, bolstering community engagement in preparedness and response, and informing response activities, including risk communication (Abramowit 2017; Bardosh et al. 2020). Despite this, much of the work has been ad hoc and not systematically integrated into the systems of epidemic response, with the exception of the Centres d’Analyses des Sciences Sociales (CASS) in the Democratic Republic of Congo (DRC). This special issue is timely, in that it builds on foundational work in social science and epidemic response, draws on tensions and experience from recent epidemics including COVID-19 and Ebola, and charts a way forward at both a theoretical and a practical level. Key Challenges/Questions in Operationalising Social Science The challenge of operationalising social science includes the need to wrestle with signifcant tensions. This includes the well-recognised tension between Anthropology in Action, 29, no. 1 (Spring 2022): 1–4 © The Author(s) ISSN 0967-201X (Print) ISSN 1752-2285 (Online) doi:10.3167/aia.2022.290101 ‘critical’ and ‘applied’ approaches, which has been long debated within anthropology (Scheper-Hughes 1995). How can we as anthropologists use our skills to support urgent epidemic response which may require working within, and thus perpetuating, and even legitimising, unequal systems, structures and power dynamics while also retaining a critical distance and independence that enables the speaking of truth to power and the reimagining and building of more equitable systems? In this issue, Luisa Enria and Shelley Lees refect on new opportunities to foreground ‘the social’ in responses to health emergencies but also to the debate on the nature of anthropological engagement. Simone Carter and Izzy Scot Moncrief, who both work at CASS, and Pierre Z. Akilimali, Dieudonné Kazadi Mwamba and Karen A. Grépin show us how social science can be rapidly mobilised to answer key questions of social diference. This tension played out in the West African Ebola epidemic, in which anthropologists were playing a series of roles that would sometimes create friction: giving voice to communities, critiquing the response and urging countries of the Global North to take responsibility, working within the response as cultural mediators (and sometimes frefghters), and infuencing policy (advocating social mobilisation and adaptation of activities to local priorities) while at the same time aiming to produce and convey research with academic rigour (Lees et al. 2020). Tensions emerged from the (dis)advantages of being ‘outsiders’ and being ‘credible advisors’ to policymakers while also retaining the expertise of ‘the local, to avoid being caught in the processes of depoliticization typical of humanitarian interventions’ (Martineau et al. 2017). In this issue, Alex Tasker and Lucy Irvine Introduction to the Special Issue Operationalising Social Science for Epidemic Response Megan Schmidt-Sane, Catherine Grant, Santiago Ripoll, Tabitha Hrynick and Syed Abbas This article is available open access under a CC BY-NC-ND 4.0 license thanks to the generous support from a global network of libraries as part of the Knowledge Unlatched Select initiative.