A Systematic Review of Discrete Choice Experiments on Preferences for COVID-19 Vaccinations

Background and Objective The COVID-19 pandemic has significantly influenced vaccination strategies and public health policies. Discrete choice experiments have emerged as a valuable tool for understanding preferences regarding vaccination. This study systematically reviews discrete choice experiments conducted on COVID-19 public vaccination preferences to identify key determinants influencing vaccine uptake and to assess methodological approaches used in these studies. Methods A systematic literature search was conducted across major databases, including PubMed, Scopus, and Web of Science, to identify discrete choice experiments focusing on COVID-19 vaccination preferences up to 31 December, 2024. Attribute categorization into five dimensions Outcome, Process, Cost, Trust, and Framing was performed and quality appraised according to the DIRECT checklist. Conditional relative importance as well as geographical differences were assessed. Results The review identified 58 studies employing discrete choice experiments that assessed public COVID-19 vaccine preferences. Among attribute categories, outcome-related factors were the most frequently used and had the highest relative importance. Other commonly evaluated attributes included cost, origin/brand, and required doses. A notable geographic disparity was observed, with studies being unevenly distributed across different regions. Methodological heterogeneity was observed in attribute selection and experimental design. Conclusions This review emphasizes the importance of considering individual preferences into vaccination strategies to enhance uptake, particularly in preparation for future pandemics. The findings reveal that vaccine effectiveness and safety are key concerns for individuals. Future research could focus on increasing representation of underexamined regions in preference studies to better inform local policymakers in developing effective vaccination programs for future health crises. Clinical Trial Registration This review was prospectively registered in PROSPERO (International Prospective Register of Systematic Reviews) with the ID CRD42025543234.