Vaccine hesitancy and refusal: history, causes, mitigation strategies

Vaccine hesitancy, referred to as the refusal or delayed uptake of vaccinations despite their availability, is one of the ten biggest current threats to global health as declared by the World Health Organization. Mistrust and outright hostility towards immunization are not recent phenomena: through the course of history, the development of new vaccinations has proceeded side-by-side with the spread of movements opposing them. The first part of this chapter recounts the salient points of the history of immunization. It provides insight into the commonalities and differences between anti-vaccination movements arising in different times and places. The historical outline is followed by an evaluation of the socioeconomic, psychological, cultural, and political factors that determine vaccine hesitancy. The final section draws on the previous two to discuss evidence-based strategies and interventions to mitigate the extent and impact of vaccine hesitancy and refusal.