Psychometric Assessment of the Italian Version of the Vaccination Attitudes Examination (VAX) Scale and Exploration of Its Link With Policy Endorsement

Two key steps in addressing the vaccination hesitancy issue are assessing the population's attitudes toward vaccination and making measures' availability as broad as possible (not limited to English-speaking populations). To reach the latter goal, we adapted the Vaccination Attitudes Examination (VAX) Scale to the Italian context. This scale has the advantages of not being vaccine-specific and of measuring individual attitudes rather than parental vaccination decisions, making it a widely adopted tool. Our scale exhibited the same desirable psychometric properties as the original version. Our investigation involved a sample of N=479 respondents showing the measurement's internal consistency and confirming the original factorial structure. Moreover, we confirmed the scale's high criterion-related validity linking greater anti-vaccination scores to previous vaccination behaviors, and we confirmed measurement invariance by running a multi-group confirmatory factor analysis comparing our current data with existing data. Additionally, we explored the scale's capabilities by linking the measure to the endorsement of infection-spreading countermeasures, a useful insight for behavioral scientists and policy-makers.