versatility is not synonymous with emergency-led responses: rather, the discontinuities, shifts and novelties have not come out of the blue. Rather, the pandemic has accelerated and legitimised their implementation. Section III: Hygienic-Sanitary Borders The Mediterranean and the Aegean seas, by themselves hostile and unsafe environments for human life, have become spaces in which migrants are not merely contained but also forcibly pushed around, often back to the places they have sought to escape from. These push-back or refoulement practices have produced (en-)forced mobilities, violently disrupting and re-directing migrant journeys across EUrope’s maritime frontiers, frequently toward the Mediterranean’s southern and eastern shores. A veritable push-back industry and environment have emerged in the Mediterranean and Aegean contexts, where thousands of migrants have been physically injured and preventively obstructed from reaching EUrope and claiming asylum. Over the past year, during the Covid-19 pandemic, existing migrant containment and deterrence measures have become reinforced and reconfigured in the name of health and safety, thus prompting what we refer to as hygienic-sanitary borders. Hygienic-sanitary aspects of borders have been noted in some recent scholarship , with Roberto Esposito developing the concept of “immunitas” that he uses to designate “a protective response in face of a risk” (Esposito, 2011: 1). Immunity, Esposito contends, is always a reaction to something which is located “on the border between the inside and the outside” (2). At the same time, immunity is predicated upon the idea that contagion and invasion could not be fully avoided: they need to be object of an “exclusion through inclusion”. Too much contamination, however, would endanger the well-being of the community and population so that the drive to protect life may indeed come to threaten or end life. Inspired by Esposito, Nick Vaughan-Williams has advanced “an ontology of the border as a biopolitical immune system” and stressed that migration is seen by states as a “degenerative contagion deemed to constitute a ‘biological risk’ to both populations and territories” (Vaughan-Williams, 2015: 116-117). Also, Henk van Houtum and Rodrigo Bueno Lacy have spoken about “EU’s autoimmunity” to stress how the border regime “consciously discriminates, endangers and criminalises the mobility of specific migrants” (Van-Houtum and Lacy, 2020: 709). Our understanding of hygienic-sanitary measures departs from these authors in a twofold way. First, we do not think of them as conceptual grids for understanding power relations, nor as an ontology of borders but, rather, as analytical descriptors able to capture ongoing 16