This thesis examines the development of active immunotherapies or ‘vaccines’ for drug addiction, within the framework of constructive technology assessment. Drawing on post-structuralist and Foucauldian critiques of medicine and constructivism derived from Science and Technology Studies it explores how addiction has come to be understood and regulated in the twenty first century in the different socio-political contexts of the UK and the US. It argues that vaccines for addiction can be seen to combine ‘old’ and ‘new’ modes of biopolitics in a flexible way, representing neither the abdication of sovereign power nor a simple continuation of the well-known biopolitical strategies of advanced liberal democracies. Part I of the thesis assesses the role of the technology as a form of anatomo-politics aimed at disciplining and normalising the individual addicted body through voluntary and coerced treatment. Part II looks at the role of prophylactic vaccination as a form of biopolitics of the population and the ways in which technologies of domination are internalised and reproduced by individuals in the context of their parental role as guardians of their children’s future health and happiness. The study is a comparative UK/ US qualitative research design, focusing on two case studies of an illegal drug (cocaine) and a legal drug (nicotine). 31 interviews were conducted in the UK and the US with key actor groups involved in the development, and potential regulation and deployment of the vaccines, and 8 focus groups with potential users in the UK. The data analysis examines the discursive construction of addiction by these groups in order to guide empirically grounded interpretations of the potential benefits and drawbacks of the use of the technology in different settings. It also considers how lay participants in the UK respond to, or challenge, the dominant clinical gaze both as active participants in the medicalisation of addiction and as sites of potential resistance. This thesis challenges the notion of the neo-liberal individual which underpins the dominant discourses of biomedicine and bioethics. It is argued that the dualism of autonomy and subjugation marginalises the subjective experiences of the patient. Specifically, it suggests that the construction of the vaccines as life-long and 100% effective directs political attention away from the benefits of harm reduction whilst also excluding alternate technologies of the self from consideration. It concludes that there is a need to widen debate in order to develop a more integrated approach to drug use and addiction.