Comparative efficacy, immune response, and safety of mRNA versus dendritic cell vaccines in solid tumors: a systematic review and meta-analysis

mRNA and dendritic cell vaccines are emerging immunotherapies for solid tumors. However, their relative immunogenicity and clinical efficacy have not been directly compared. We aimed to evaluate the comparative immune response, tumor response, safety, and survival outcomes of mRNA versus dendritic cell vaccines in patients with solid tumors. We performed a systematic review and network meta-analysis of clinical trials assessing mRNA and dendritic cell cancer vaccines in patients with solid tumors. We included 60 unique studies (67 trials) with a total of 1777 patients. Outcomes evaluated included immunogenicity (immune response), tumor response (objective response rate and disease control rate), safety (incidence of mild and severe adverse events), and survival (overall and progression-free survival). The review was prospectively registered in PROSPERO (No. CRD420251012772; registered 17 March, 2025). mRNA vaccines elicited significantly stronger immune responses than dendritic cell vaccines. mRNA vaccine recipients also experienced a higher incidence of adverse events, including mild and severe events. By contrast, dendritic cell vaccines achieved significantly higher objective response and disease control rates. No significant differences in overall survival or progression-free survival were observed between the two vaccine groups. Despite moderate between-trial heterogeneity, the findings were consistent and robust across analyses. This comprehensive network meta-analysis provides the first comparative evaluation of mRNA versus dendritic cell vaccines in solid tumors. It indicates that while mRNA vaccines induce more potent immunogenicity, dendritic cell vaccines confer better tumor control, with no observed differences in survival outcomes. These findings fill a critical evidence gap and provide an exploratory synthesis highlighting potential strengths and limitations of each vaccine type. Given that most included studies were early-phase, small-sample trials, these findings should be considered hypothesis-generating and interpreted with caution.