evidence: Cancer vaccines are a subtype of immunotherapy, based on the same underpinning principle as vaccines against infectious disease. The idea is that by showing the immune system what an invading pathogen or cancer cell looks like, you can teach it to quickly recognise and destroy them if it encounters them again. [...] Researchers are exploring the use of various platforms to develop cancer vaccines. These include whole cell vaccines, which use whole cancer cells to trigger an immune response, and protein- or peptide-based vaccines, which expose the immune system to specific proteins or fragments of proteins from cancer cells. [...] Numerous mRNA-based cancer vaccines are currently in clinical trials for various types of cancer.