  This study presents survey results of the public's willingness to get
vaccinated against COVID-19 during an early phase of the pandemic and examines
factors that could influence vaccine acceptance based on a between-subjects
design. A representative quota sample of 572 adults in the US and UK
participated in an online survey. First, the participants' medical use
tendencies and initial vaccine acceptance were assessed; then, short vignettes
were provided to evaluate their changes in attitude towards COVID-19 vaccines.
For data analysis, ANOVA and post hoc pairwise comparisons were used. The
participants were more reluctant to vaccinate their children than themselves
and the elderly. The use of artificial intelligence (AI) in vaccine development
did not influence vaccine acceptance. Vignettes that explicitly stated the high
effectiveness of vaccines led to an increase in vaccine acceptance. Our study
suggests public policies emphasizing the vaccine effectiveness against the
virus could lead to higher vaccination rates. We also discuss the public's
expectations of governments concerning vaccine safety and present a series of
implications based on our findings.
