Pro-vaccination communication requires tailoring: Evidence from an experimental and longitudinal comparison of communication strategies on vaccination-related cognition and intentions

Effective vaccination communication requires evidence-based strategies, yet direct comparisons are scarce. In a longitudinal experiment (N = 901, four time points), we compared six pro-vaccination communicative texts —nudge, boost, psychological inoculation (PI), patient-concerns-centred communication (PCCC), dismissive informational load (DIL), and neutral informational load (NIL)—against a control. We assessed the immediate and sustained impact on vaccination intention (personal and proxy), information-seeking habits, and vaccine-related biased reasoning. No single communication strategy was universally superior; effectiveness depended on the decision context and pre-existing attitudes. PCCC most effectively increased immediate personal vaccination intention, while NIL increased intention to vaccinate a child. Pre-existing attitudes and beliefs were strong moderators of effect (e.g., PI and NIL were more effective for individuals reporting higher vaccine conspiracy beliefs when making proxy decisions). Critically, our findings reveal what these brief interventions can and cannot achieve: while initial gains in intention from PCCC and NIL remained stable, the impact on information-seeking habits was modest, and these brief-exposure interventions were insufficient to alter ingrained cognitive processes, such as vaccine-related biased reasoning. While brief communication can shift immediate intentions, changing how people think requires more sustained efforts. We argue that communication must be tailored to the audience and decision type, emphasising the importance of considering patient concerns and suggesting abandoning the DIL approach given its tone and ineffectiveness.