Conspiracy Beliefs, Secondary Risk Perceptions, and Conditional Acceptance of Dengue Vaccine: A Multigroup Comparison Based on Prior COVID-19 Vaccination Experiences

This study investigates the pathways linking general vaccine conspiracy beliefs to the conditional acceptance of the dengue vaccine, with a particular focus on the mediating role of secondary risk perceptions and the spillover effects of prior COVID-19 vaccination experiences. Based on an online survey of 1,001 Singaporeans and permanent residents, we found that stronger vaccine conspiracy beliefs were associated with heightened perceptions of secondary risk severity and susceptibility related to dengue vaccination, which, in turn, were linked to less favorable attitudes toward the dengue vaccine. These attitudes were positively associated with conditional acceptance of the dengue vaccine. Moreover, perceived secondary risks and attitudes toward the dengue vaccine served as sequential mediators in the relationship between vaccine conspiracy beliefs and conditional acceptance. Additionally, a multigroup analysis revealed that the associations between perceived secondary severity and susceptibility of dengue vaccination and attitudes toward the dengue vaccine varied depending on the level of side effects individuals experienced from their prior COVID-19 vaccination. Theoretical and practical implications are discussed.