Therapeutic Cancer Vaccines: Current Evidence on Immunogenicity, Clinical Efficacy, Safety, and Emerging Challenges.

Abstract

Background:

Cancer is a leading cause of death globally and is significantly more difficult to treat than other diseases owing to tumor heterogeneity. Treatment of advanced cancers with conventional therapies such as chemotherapy or checkpoint inhibitors is plagued by a high incidence of recurrence and treatment resistance. The high specificity of cancer vaccines and their ability to target multiple neoantigens simultaneously provide avenues for circumventing tumor heterogeneity. This review aimed to provide a comprehensive overview of the current literature on cancer vaccines, with particular emphasis on their immunogenicity, efficacy, and safety.

Methodology:

PubMed and Web of Science databases were searched for primary research articles on cancer vaccines published in English within the past five years and available free of charge. A total of 45 articles were included in the review. Findings were stratified according to vaccine platform into nucleic acid, peptide, cell-based, and vector-based vaccines.

Results:

Cancer vaccines across all platforms demonstrated significant immunogenicity, including long-term immune responses. Vaccine-induced immune responses were observed in CD8+ and CD4+ T cells as well as B cells. Substantial, although ultimately inconclusive, clinical efficacy was reported across vaccine platforms. The greatest clinical benefit was observed when cancer vaccines were administered in the adjuvant setting; however, clinical benefit was not consistently correlated with immunogenicity. Cancer vaccines also demonstrated a safety profile that was generally preferable to that of conventional therapies. Small, uncontrolled trials and lengthy and expensive production processes were identified as major challenges in the field.

Conclusion:

Cancer vaccines demonstrate considerable potential as safe and effective therapeutic strategies to supplement conventional approaches to cancer treatment. However, further well-designed research is required to establish definitive effect sizes, clarify the relationship between immunogenicity and clinical benefit, and overcome practical barriers to their widespread clinical implementation.