Breast cancer, the most diagnosed malignancy globally, poses a significant health burden, with approximately 2.3 million new cases and 700,000 deaths annually. Breast cancer vaccines represent an innovative approach to prevention and treatment, harnessing the immune system to target tumor-specific antigens such as α-lactalbumin, HER2, and MUC1. Prophylactic vaccines aim to reduce risk in high-risk groups like BRCA1/2 mutation carriers, while therapeutic vaccines, particularly for triple-negative breast cancer, stimulate T-cell responses to combat aggressive tumors. Advances in mRNA technology, nanoparticle delivery, and neoantigen identification enhance vaccine precision and efficacy. However, challenges including tumor heterogeneity, immune evasion, and production scalability limit clinical success. Ongoing phase I and II trials explore combination therapies with checkpoint inhibitors and antibody-drug conjugates to overcome these barriers. This review examines the current landscape, mechanisms, and challenges of breast cancer vaccines, highlighting their potential to transform oncology through personalized, less invasive strategies.