The seasonal influenza vaccination is an effective preventive measure and a common ingredient of workplace health promotion. However, many employees do not participate. The present study aimed to analyse vaccination motivation as a basis for future intervention to increase the proportion of participants. To this end, 1,466 employees of a German company were asked to fill in a questionnaire. The results document a relationship between past vaccination behaviour and intention to be vaccinated, mediated by outcome expectancies. However, past behaviour represented a substantial moderator in this interplay. The indirect effect was only apparent for individuals who did not undergo the annual vaccination. Vaccination campaigns should therefore take past vaccination behaviour into consideration. Positive and negative outcome expectancies seem to be motivating only when individuals have not or have only rarely taken part in the annual vaccination. In contrast, people who participate annually apparently form their intention independent of outcome expectancies, i.e., they make a decision without elaborating pros and cons of vaccination. Their intention is rather evoked automatically when the appropriate stimulus is presented.
