[Individualized immunotherapy for malignant tumors using peptide vaccines-maybe it does work after all?]

The physician and scientist Paul Ehrlich put forward the thesis that the immune system not only fights infections but can also fight cancer. The possible positive effects of a simultaneous infection on the course of cancer were reported in ancient Egypt around 2600 BC. However, it was not until the 1960s that it became apparent that the immune system could specifically fight cancer cells, and it was not until the 1990s that researchers slowly clarified how this happens.Against this background, the efforts over the last 30 years to develop therapeutic vaccines against cancers are briefly summarized, and their lack of success to date is highlighted. In addition, potentially promising future developments in this context are discussed. The available scientific literature as well as our own results are taken into account.Central questions arise, such as the following: How do cancer cells differ from normal cells? How can the immune system recognize these differences? What are tumor-specific antigens? Why do they need to be selected and applied in an individualized fashion? How can an efficient immune response be induced? Which pharmaceutical formulations, adjuvants, and vaccination routes are effective?Finally, we explain why it may still be worth pursuing peptide vaccination, which has so far been completely unsuccessful (when measured in terms of already approved therapeutics).