Abstract The main objective of VAX-ACTION is to support EU Member States and relevant stakeholders to implement the results of tailored, evidence-based interventions aimed to reduce vaccine hesitancy. Based on the evaluation of effectiveness of these interventions, which will be conducted in selected target regions in EU member states, recommendations will be drawn through diverse dissemination strategies to allow scaling up good practices to other member States, but also to the USA and Canada, where gaps in implementation strategies also have prevented effective, evidence-based interventions aimed to better deal with vaccine hesitancy. The first phase of the research involved some relevant systematic reviews with the aim of: 1. to map public health evidence and research results on large-scale vaccination programs in Europe and north America; 2. to map interventions aimed to address vaccine hesitancy regarding new and well-stablished vaccines and vaccination programs (Covid-19, mpox, national immunizations programs for children) in Europe and north America; 3. to identify successful and unsuccessful interventions designs aimed to address vaccine hesitancy, including challenges in the implementation, evaluation designs, and the feasibility of scaling-up solutions that are context-sensitive; 4. to identify significant similarities or dissimilarities in the designs and outcomes of interventions aimed to address vaccine hesitancy in northern countries where political and academic concern towards this phenomenon is growing; 5. to identify the extent to which ‘grounding’ (bottom-up) experiences aimed to address vaccine hesitancy are evidence-based, build on current international knowledge and guidelines, and whether they are internationally reported; 6. to systematize the mapping of interventions aimed to address vaccine hesitancy in the northern hemisphere in a way that can be shared and used by third parties. This contribution will illustrate the results of the first phase of the project.