Viral infections lead to alarmin release and elicit potent cytotoxic effector T lymphocyte (CTLeff) responses. Conversely, the induction of protective tumor-specific CTLeff and their recruitment into a tumor remain challenging tasks. Here we show that lymphocytic choriomeningitis virus (LCMV) can be engineered to serve as a replication competent, stably-attenuated immunotherapy vector (artLCMV).