ABSTRACT
Since COVID-19 was declared a global pandemic, scholars and practitioners have put much effort into testing effective advertising strategies for COVID-19 vaccinations. Guided by humor theories, this study aimed to examine (1) the effect of humor on persuading COVID-19 vaccination and (2) the moderating role of trust in government for the unvaccinated population. Across two studies (college students and general adult populations), for lower trust in government individuals, through greater public service advertisement (PSA) processing depth and believability, there was a higher vaccination intention after the humor (non-humor) advertisement. For higher trust in government individuals, there was evidence that the vaccination intention was lowered after the humor (vs. non-humor) message through lowered PSA processing depth and believability. This study expands humor theory into testing COVID-19 vaccination messages while considering an individual psychological factor, trust in the government, that has emerged as an essential determinant to COVID-19 messaging. The contributions to COVID-19 vaccination advertising strategy and advertising to the unvaccinated population, in general, are discussed.