Vaccination planning. We measured vaccination planning by assessing respondents' agreement on a 5-point scale with three statement items, such as ''I have planned when and where to get my human swine flu vaccination this winter''. The internal consistency a for these three items was 0.59, though less than the most common acceptable level of above 0.7, remaining at the minimal acceptable level (a ranged between 0.5-0.6) of reliability for preliminary research [56] . These items were also treated as indicators of a latent variable for modeling purposes.