Reprogramming the tumor microenvironment through vaccine strategies to improve clinical outcomes and guide future innovations.

The tumor microenvironment (TME) is a dynamic, multilayered ecosystem composed of immune cells, stromal elements, vascular structures, extracellular matrix components, and soluble mediators that collectively shape tumor progression, immune evasion, and therapeutic resistance. Vaccines targeting the TME represent an emerging paradigm in cancer immunotherapy, aiming not only to elicit antigen-specific T-cell responses but also to remodel immunosuppressive niches that characterize immune-desert and immune-excluded tumors. By directing immune activation toward non-malignant but functionally critical components—including cancer-associated fibroblasts (CAFs), regulatory T cells (Tregs), tumor-associated macrophages (TAMs), and angiogenic pathways such as VEGF signaling—TME-targeted vaccines seek to convert “cold” tumors into immunologically responsive states amenable to combination treatment. This narrative review synthesizes major advances from 2023 to 2025 in antigen selection strategies, vaccine delivery platforms, clinical developments, and mechanistic insights underlying TME reprogramming. Key challenges, including stromal heterogeneity, cytokine-driven immunosuppressive rebound, and delivery inefficiencies, are examined alongside safety considerations and translational barriers. Future directions—such as integration with immune checkpoint inhibitors, targeting immunometabolic checkpoints like CD39, leveraging macrophage reprogramming approaches, and implementing AI-guided vaccine personalization—are discussed to highlight opportunities for durable tumor control. By consolidating current evidence and outlining emerging innovations, this review aims to support ongoing efforts to advance next-generation TME-directed immunotherapies within the framework of precision oncology.