Reducing vaccine hesitancy by explaining vaccine science.

Vaccine hesitancy in the COVID-19 pandemic remained a problem long after mRNA vaccines became available. This may be due in part to misunderstandings about the vaccines, arising from complexities of the science involved. Two experiments, conducted on unvaccinated Americans at two periods postvaccine rollout in 2021, demonstrated that providing explanations, expressed in everyday language, and correcting known misunderstandings, reduced vaccine hesitancy compared to a no-information control group. Four explanations addressing misunderstandings about mRNA vaccine safety and effectiveness were tested in Experiment 1 ( = 3,787). Some included expository text while others included refutational text, explicitly stating and refuting the misunderstanding. Vaccine effectiveness statistics were expressed either as text or an icon array. Although all four explanations reduced vaccine hesitancy, the refutational format of those addressing vaccine safety (explaining the mRNA mechanism and mild side effects) was the most effective. These two explanations were retested individually and jointly in Experiment 2 ( = 1,476) later in the summer of 2021. Again, vaccine hesitancy was significantly reduced by all explanations despite differences in political ideology, trust, and prior attitudes. These results suggest that nontechnical explanations of critical issues in vaccine science can reduce vaccine hesitancy, especially when accompanied by refutational text. (PsycInfo Database Record (c) 2023 APA, all rights reserved).