Despite significant advances in cancer therapy, the prognosis for patients with advanced, disseminated disease remains poor. This underscores the urgent need for novel treatments that not only eliminate tumor cells effectively but also stimulate a strong, durable anti-cancer immune response. Among emerging strategies, oncolytic viruses have shown exceptional promise due to their selective cytotoxicity and their ability to activate T cell-mediated immune responses. In this review, we focus on the vaccinia virus (VACV), a member of the Poxviridae family, which has emerged as a leading candidate in modern oncolytic immunotherapy. We examine the virus’s properties that enable it to evade antiviral defenses and serve as a versatile, potent oncolytic agent. Furthermore, we explore its interactions with various components of the immune system and how these contribute to the induction of a robust T cell-driven response. Finally, we assess current efforts to harness VACV for the treatment of various cancer types and highlight future directions where its application is most likely to succeed. Overall, our goal is to present VACV as a powerful and broadly applicable platform with the potential to transform the landscape of oncology.

Despite significant advances in cancer therapy, the prognosis for patients with advanced, disseminated disease remains poor. This underscores the urgent need for novel treatments that not only eliminate tumor cells effectively but also stimulate a strong, durable anti-cancer immune response. Among emerging strategies, oncolytic viruses have shown exceptional promise due to their selective cytotoxicity and their ability to activate T-cell-mediated immune responses. In this review, we focus on the vaccinia virus (VACV), a member of the Poxviridae family, which has emerged as a leading candidate in modern oncolytic immunotherapy. We examine the virus's properties that enable it to evade antiviral defenses and serve as a versatile, potent oncolytic agent. Furthermore, we explore its interactions with various components of the immune system and how these contribute to the induction of a robust T-cell driven response. Finally, we assess current efforts to harness VACV for the treatment of various cancer types and highlight future directions where its application is most likely to succeed. Overall, our goal is to present VACV as a powerful and broadly applicable platform with the potential to transform the landscape of oncology