Vaccination is one of the most recognised strategies in public health for preventing the spread of epidemics, and the availability of a vaccine is often expected by health actors to be a 'game-changer'. However, the COVID-19 (coronavirus disease 2019) vaccine in Senegal was not the magic bullet that the international community expected. A very low vaccination coverage rate (less than 10% by April 2023) was observed in this country, once considered a model in West Africa for its epidemic response. Beyond the population's alleged hesitancy to be vaccinated, was a lack of preparedness to blame? Previous analyses show that outbreak preparation limited to standard interventions is not sufficient in the face of the social, cultural, and political configurations of each epidemic context and that uncertainty limits response capacity. This paper examines the social life of the COVID-19 vaccine to identify the forms and contextual dimensions of uncertainty related to immunisation in Senegal. The authors explore how vaccination was implemented and compare experiences with the preparedness process, to offer insight on uncertainties. Using Stirling's theoretical model that defines various expressions of incertitude, the authors identify four nexuses at various stages of the social life of COVID-19 vaccine in Senegal: (1) material uncertainty related to vaccine availability, (2) ambiguity of the population about the purpose of vaccination and the risks of the disease, (3) uncertainty related to side effects, and (4) uncertainty about vaccination strategies shared by scientific and health authorities. These uncertainties were only partly considered in the preparedness process, for they are related to systemic structural dimensions and reflect the impact of global/regional powers on the local level. The findings of this research are relevant not only to support better communication around vaccines in Senegal but also more generally to the prevention of emerging epidemics shaped by human behaviours.
