Archive | 2021
COVID-19 Vaccine Hesitancy in Eight European Countries:\nPrevalence, Determinants and Heterogeneity
Abstract
\n Vaccine hesitancy poses a major obstacle to containing COVID-19. Previous experimental studies of communication strategies for promoting COVID-19 vaccine uptake have been conducted in a single country each, often testing strategies that have differed from those studied in other countries. On the few occasions when two or more single-country studies have tested similar treatments, they have yielded inconsistent findings. For example, highlighting pro-social benefits increased participants’ willingness to get vaccinated in the UK and the US, but had no effect in France and the UK, thus calling into question the often implied generalisability of previous findings. We experimentally assess the effectiveness of different information treatments across eight European countries and examine heterogeneity in the willingness to get vaccinated against COVID-19, as well as in the perceptions of the different vaccines available, within and across countries. We reveal striking differences in COVID-19 vaccine hesitancy across countries, ranging from 5.5% of the adult population in Spain to 50.94% in Bulgaria. The main barriers to vaccine acceptance were fears regarding the quality and safety of the vaccines, as well as mistrust in government. Receiving information emphasising (i) COVID-19 risk reduction through vaccination, (ii) non-medical benefits of a vaccination certificate, and (iii) hedonistic benefits significantly increases vaccination willingness in Germany, but only the vaccination certificate message significantly increases willingness in the UK. No information treatment has significant effects in any other country. A machine-learning technique, model-based recursive partitioning, reveals that the effectiveness of some information treatments is highly heterogeneous among subsets of the population, with adverse effects for Spanish, German and Italian participants without active employment. The heterogeneity of vaccine hesitancy and responses to different messages suggests that health authorities should avoid one-size-fits-all messages and instead tailor vaccination campaigns to their specific target populations, with special care to more disadvantaged populations.