Scenario variables, vaccination program attributes and their levels included in the DCE survey.

Notes: Levels of the no vaccination option were defined as: not applicable (n.a.), no side effects, n.a., n.a., €0 respectively. The scenario variables were the same across all alternatives in one choice set. Abbreviation used: RIVM = Dutch abbreviation of National Institute for Public Health and the Environment. (1) Defined as the proportion of population infected with the new disease, i.e. having symptoms. (2) Defined as the proportion of infected population that suffered severe symptoms (death, life-threatening events, hospitalization and severe or permanent handicap). (3) The attributes ‘safety of the vaccine’, ‘advice about the vaccine’ and ‘media coverage about the vaccine’ entered the analysis as categorical variables. (4) Long term severe side effects (death, life-threatening events, hospitalization, severe or permanent handicap, or side effects leading to birth defects to an unborn fetus). Before the start of the choice tasks, respondents were informed that on the short term, vaccinations resulted in mild side effects only. (5) Traditional media were defined as: radio, newspapers and television. (6) Social/interactive media were defined as: blogs, Twitter and social network websites.