Vaccine literacy among Italian travelers: A web-based survey using a brief assessment tool

The convergence of emerging infectious diseases, accelerating ecological changes, and increasing global mobility makes Vaccine Literacy (VL) a critical component of contemporary travel medicine. Enhanced VL can facilitate more effective provider-traveler communication, ultimately reducing infectious disease transmission risks associated with international travel. This cross-sectional survey aimed to measure VL levels among Italian travelers through an online survey using the 'Vaccine Literacy Brief Tool' (VLBT), a new three-item instrument assessing functional, interactive, and critical dimensions, derived from previously validated measures. Additional study objectives were to explore VL relationships with antecedents, attitudes, and outcomes, as well as to establish the tool's construct and criterion validity within the traveler population. Enrollment was conducted through a QR code displayed at nine vaccination clinics across five Italian regions, linking to an anonymous questionnaire (Google Forms) that visiting travelers could voluntarily access and complete before receiving vaccination for their trip. In addition to VL skills, the psychological antecedents of Vaccine Hesitancy (VH), the "3Cs" (confidence, complacency, convenience) were assessed. Additional measures included demographic and travel-related variables, as well as behavioral, cognitive and intentional vaccination outcomes. A total of 534 questionnaires were collected between January and July 2025. Participants showed a mean VL score of 3.07 ± 0.66 on a four-point Likert scale, significantly lower than the 3.21 ± 0.42 reported in previous general population studies (<i>p</i> < .001). The mean 3Cs score was 1.92 ± 0.60, indicating relatively high VH levels. VL and 3Cs scores showed a significant negative correlation (r = -0.204, <i>P</i> < .001). Participants consisted primarily of highly educated adults aged 18-40 years. VL scores were negatively associated with younger age (ρ = -0.132, <i>p</i> = .002), and positively with higher educational level (ρ = 0196, <i>p</i> < .001), higher income (ρ = 0.145, <i>p</i> < .001), greater number of information sources consulted (r = 0.104, <i>p</i> = .016), and more favorable vaccination outcomes. Conversely, the 3Cs demonstrated inverse significant relationships with the same demographic and behavioral variables. No significant gender differences emerged for either VL or 3Cs measures. Construct validity of the VLBT was supported by the significant negative correlation between VL and 3Cs scores, and with additional confirmation provided through reliability tests and factor analyses. Criterion validity was demonstrated through significant associations between VL scores and vaccination behaviors: number of vaccines received, vaccination recall accuracy, awareness of destination-specific pre-travel vaccination requirements, and influenza vaccination intention. Mediation analysis revealed that the 3Cs partially mediated the relationship between VL and specific vaccination intention outcomes, while demographic characteristics (age, income) and travel-related factors (number of information sources) significantly moderated these associations. The VLBT assessed travelers' VL levels through three simple questions and demonstrated potential clinical utility in travel medicine. By facilitating identification of individuals with limited literacy levels, the new tool can help providers orientate the discussion for a profitable counseling session. Implementation research is needed to confirm its effectiveness in routine travel clinical practice. The high VH revealed in the traveler population warrants future targeted research.