The main so-called conventional anti-tumoral treatments are based on surgery, radiotherapy and chemotherapy. Many cancers do not respond or fail to respond to these treatments. Immunotherapy, which consists of educating the immune system to be able to fight effectively and specifically against cancer cells, is a promising new approach. Based on this concept, therapeutic cancer vaccines, capable of boosting the immune system to fight cancer, but also capable of inducing a memory response, could also prevent relapses. Many pathways are explored, especially living microorganisms for their lytic activity vis-à-vis tumour cells and/or their ability to stimulate the immune system. Thus, in recent years, pathogen-based oncolytic therapies have emerged in the anti-tumoral therapeutic arsenal. The first virotherapy based on the use of a genetically modified GM-CSF expressing herpes virus to target tumour cells has just been approved by the FDA for the treatment of melanomas (Imlygic®, Amgen). More recently, the Bristol-Myers Squibb and Janssen pharmaceutical laboratories have partnered to collaborate on clinical trials on the clinical efficacy of Opdivo® (nivolumab) and the attenuated bacterium Listeria monocytogenes dan...