Understanding the Dimensions of Anti-Vaccination Attitudes: the Vaccination Attitudes Examination (VAX) Scale

BACKGROUND: Anti-vaccination attitudes are important predictors of vaccination behavior. Existing measures of vaccination attitudes focus on specific age groups and/or particular vaccines; a more comprehensive measure would facilitate comparisons across studies. PURPOSE: The aim of this study was to develop a short measure of general vaccination attitudes and establish its reliability and validity. METHODS: Two studies were conducted using the VAX scale. For Study 1, participants were 409 individuals (53% female), with a mean age of 34.5 years. For Study 2, participants were 92 individuals (67% female) with a mean age of 28.6. Participants answered paper-and-pencil questions about their attitudes toward vaccines, prior and expected-future vaccination behaviors, perceived sensitivity to medicines, online behavior, and basic demographic information. Exploratory and confirmatory factor analyses were conducted with correlations and t tests then used to assess the scale's reliability and validity. RESULTS: Four distinct but correlated vaccine attitudes were identified: (1) mistrust of vaccine benefit, (2) worries about unforeseen future effects, (3) concerns about commercial profiteering, and (4) preference for natural immunity. These factors were significantly related to prior vaccination behavior, future intentions to obtain recommended vaccinations, perceived sensitivity to medicines, and the tendency to obtain health information online. CONCLUSIONS: The VAX scale provides an efficient method for identifying those with vaccination resistance, and the four subscales enable a more nuanced understanding of the nature of those views. It should be noted, however, that the strong correlations amongst the four subscales suggest that interventions should target all four attitude areas, and it remains to be seen whether differential emphasis across the four areas is warranted.