Vaccination Readiness and Conspiracy Beliefs to Virus-Based Diseases: A Validation Study.

Individuals' conspiracy beliefs can influence their vaccination readiness, which may affect the annual vaccination uptake rate for infectious diseases such as influenza and COVID-19. To provide reliable and valid tools adapted to the Taiwanese context in assessing these two constructs, the present study validated the psychometric properties of four scales among Taiwanese adults: the COVID-19 Vaccination Readiness Scale (CVRS), Influenza Vaccination Readiness Scale (IVRS), Influenza Conspiracy Beliefs Scale (ICBS), and COVID-19 Conspiracy Beliefs Scale (CCBS). A total of 914 participants completed the online survey between October and November, 2024. Confirmatory factor analysis (CFA) was employed to confirm the model structures and factor loadings for the four scales. All fit indices for all the scales were acceptable, with CVRS and IVRS fitting well to a bifactor model-general and specific-(comparative fix index [CFI] = 0.936 and 0.943) and the CCBS and ICBS to a two-factor model (CFI = 0.961 and 0.973). The internal consistency assessed by Cronbach's alpha [α] and McDonald's omega [ω] was good among all scales (α = 0.87, 0.87, 0.93 and 0.96; ω = 0.90, 0.91, 0.95 and 0.97, for CVRS, IVRS, CCBS and ICBS). Moreover, conspiracy beliefs negatively correlated with vaccination readiness (r = -0.351 to -0.417, p < 0.01). The robustness of these scales was validated. Moreover, conspiracy beliefs were associated with vaccination readiness. Authorities may use these scales to understand individuals' thoughts on vaccination and inform promotion strategies. Future studies may consider these variables in other types of infectious diseases, such as Mpox.