BackgroundAcross various stages of the COVID-19 pandemic and related vaccine recommendations in France, we assessed the association of the 7C-psychological antecedents with vaccine uptake/intention for booster vaccination among healthcare-sector workers (HCSWs). We also assessed whether 7C-antecedent profiles change over time. MethodologyThe Research Group for the Prevention of Occupational Infections in Healthcare Workers(GERES) conducted three repeated web-surveys which were disseminated by email chain-referral among HCSWs throughout France. The questionnaires waves took place: July-November2021, February-March2022 and January-March2023 (P2, P3 and P4). We also reanalysed data from a prior similar study conducted late2020-early2021 (Moirangthem et al. (2022)) (P1). To evaluate the association of 7C-items with vaccine uptake-intention for future vaccination, we estimated adjusted prevalence ratios(aPR) through robust variance Poisson regression. We report the 7C-item population attributable loss in vaccine intention. ResultsThe four surveys (P1-P4) encompassed 5234, 339, 351 and 437 participants. At earlier stages of the vaccine campaign, the principal antecedents of vaccine intention were favorable perception of vaccination benefit-risk-balance (BRB)(vs. unfavorable, aPR:2.32), reactance to employer encouragement for vaccination (motivates vs. dissuades-me, aPR:2.23), vaccine confidence (vs. not-being-confident, aPR:1.71) and social conformism towards vaccination (favorable vs. skeptical opinion in private environment, aPR:1.33). Under a vaccine mandate for HCSWs, only perceiving vaccination as a collective action was associated with current vaccine status (agree vs. disagree, aPR:2.19).At later stages of the epidemic, hypothetical booster vaccine intentions, were strongly associated with BRB perception (favorable vs. unfavorable, aPR:2.07) and perceiving vaccination as a collective action (agree vs. disagree, aPR:1.69). Not being confident in vaccines decreased population vaccine intention by 26.16%. In longitudinal follow-up of seven participants, relatively stable attitudes were observed only for vaccination as collective action and capacity for reactance. ConclusionOur results suggest that both 7C-antecedents and their association with vaccine behaviour can change over time and the importance to increase confidence in vaccines.