The present invention generally relates to a personalized cancer vaccine comprising a recombinant poxvirus encoding one or more neopeptide(s) or a composition comprising such a recombinant poxvirus and a pharmaceutically acceptable vehicle as well as the use of said personalized cancer vaccine for treating a cancerous subject in need thereof. A specific embodiment is directed to a method of providing such a vaccine or composition comprising an identification step comprising a) extracting the DNA from a tumor sample and a non-tumor sample, b) selecting target regions, preferably the entire coding regions of the genome (exome), c) sequencing said target regions (e.g. the exome) from said extracted DNAs and d) identifying one or more tumor-specific mutation(s) by comparing the DNA sequences obtained from said tumor and non-tumor samples. Embodiments also include a method of treating cancer or preventing its relapse comprising administration of such a personalized cancer vaccine. The invention is of very special interest in the field of personalized immunotherapy, specifically for stimulating T cell immune response.