I Want To Be Safe: Understanding The Main Drivers Behind Vaccination Choice Throughout The Pandemic

Abstract Background Vaccines are one of the most significant achievements of modern medicine. However, vaccine hesitancy and refusal are widespread and can hamper immunization campaigns. During the COVID-19 pandemic, vaccine hesitancy became particularly evident. Beliefs regarding vaccine efficacy and safety are prominent in shaping vaccine acceptance rates. This study investigated the impact of efficacy and safety perception on vaccine uptake in Italy throughout the pandemic. Methods We used a 70-item questionnaire distributed to a representative sample of 600 Italian speakers. The participants were asked to rate how effective/safe they perceived each vaccine dose and their willingness to receive a potential fourth dose. Results Our findings show that vaccine efficacy and safety perception changed during the pandemic, possibly shaping vaccination compliance. If at the time of the first dose the vaccine was deemed as more effective than safe, at the time of the third dose the assessment was reversed. Moreover, regarding a potential future vaccination, the role of beliefs regarding efficacy is negligible, whereas the role of beliefs regarding safety appears as still significant. The results of our experimental manipulation (framing effect) highlighted that framing vaccine-related information in terms of safety is much more effective that framing it in terms of efficacy in boosting the willingness to vaccinate. Moreover, we retraced the diachronic evolution of the reasons behind vaccination choice. We detected a decrease in infection-related reasons and a corresponding increase in social-related ones. Lastly, we reported a different evolution of trust attribution relative to public authorities and the scientific community. Conclusions The perception of vaccines is a constantly evolving process, influenced by various dynamic factors such as perception of efficacy and safety, levels of trust, and individual motivations. Our study sheds light on the complex dynamics that underlie the perception of vaccine safety and efficacy, and their impact on willingness to vaccinate. We discuss these results in light of bounded rationality, loss aversion and classic utility theory. This study traces the pandemic history in Italy by examining the evolution of beliefs, opinions, and trust of a representative sample of the population.