The Potential and Challenges of the Cancer Vaccine for the Prevention and Treatment of Cancers

Vaccines elicit immune defenses against a particular pathogen by delivering antigens, molecules, or molecular fragments that trigger an immune response. Cancer vaccines represent a transformative and promising frontier in oncology, aiming not only to prevent malignancies but also to treat established tumors by harnessing the immune system. Prophylactic vaccines, such as those targeting cancer-related viral antigens, have successfully reduced the incidence of virus-induced cancers. Therapeutic cancer vaccines—particularly those targeting tumor-specific neoantigens—have shown promise but face substantial biological and translational challenges. This review summarizes current progress in both prophylactic and therapeutic cancer vaccines, focusing on antigen targets, delivery platforms, and clinical development. We discuss major barriers, including tumor heterogeneity, immune tolerance, and immunosuppressive tumor microenvironments, as well as translational challenges such as manufacturing complexity, cost, and scalability. Finally, we highlight emerging strategies—including mRNA platforms, artificial intelligence (AI)-guided antigen selection, and combination immunotherapies—aimed at overcoming these limitations and improving clinical efficacy.