Cancer vaccines: An unkept promise?

Two decades ago, cancer vaccines were hailed as a prominent breakthrough for the treatment of cancer. However, the vaccines failed to show any improvement in median survival time in various clinical trials, even though they stimulated the immune response and showed exceptional safety profiles. The resistance of cancer cells to the immune response was revealed as a significant hurdle. In this review, I discuss the different types of cancer vaccines and the strategies used to design them. I also highlight how cancer cells develop resistance to the immune response, and how therapies, such as monoclonal antibodies (mAbs) and small interfering (si)RNA/short hairpin (sh)RNA could be used to address some of the shortcomings of cancer vaccine treatments.