Revisiting the concept of 'vulnerability'.

The terms 'vulnerable' and 'vulnerability' are used more and more frequently in the areas of both social science research into and prevention of HIV/AIDS, but certain difficulties arise when it comes to applying this concept to actual situations at the heart of which individuals or groups are more exposed to HIV. The concept of vulnerability must thus be clarified to reinforce its heuristic capacity and political and practical relevancy. The first part of this paper is devoted to presenting a heuristic matrix of vulnerability, used in previous research among people living with HIV/AIDS (PWHAs) and to extracting three levels of intelligibility, that is to say, first the social trajectory level, then the level on which two or more trajectories intersect, and finally that of the social context. Each of the elements belonging to these three levels must be described both objectively and subjectively. The identity construction processes are then proposed as particular observation and 'gelling' points for these various levels taken as a whole. In the second part of the paper, we have reviewed how the concept of 'vulnerability' has been defined and used in other fields, notably disaster, famine, and mental health, paying special attention to the crucial points in the debates that are raging in these fields. We have also shed light on a few concepts that are frequently associated with vulnerability, such as victimization, insecurity, and risk. In the third part, we have summarized our approach to vulnerability as a relevant concept for elucidating risk-taking processes and designing intervention programmes. The importance of analysing the inter-individual differences, the variability in time and the relational dimension of all social vulnerability has been stressed.