Vaccinia virus-mediated oncolytic immunotherapy: Emerging strategies for gastrointestinal cancer treatment at dawn.

Oncolytic vaccinia virus (VVs) based immunotherapy is a rapidly developing treatment for gastrointestinal (GI) cancers. Conventional treatments, such as chemotherapy, radiotherapy and surgery achieve good effects in early-stage GI cancers, but effects are limited in advanced disease. Immunotherapy has limited efficacy in GI cancers due to tumor heterogeneity and complex immunosuppressive mechanisms. Oncolytic VV immunotherapy is a novel treatment approach showing promising results in preclinical and clinical trials. Oncolytic VV's intracytoplasmic replication and assembly mechanism, diverse mature forms, and use methods make it extremely safe and versatile for drug delivery. Combining oncolytic VV with conventional therapies and immunotherapy (e.g., ICIs, CAR-T) enhances tumor regression and survival compared to monotherapies. Researchers are establishing response protocols and improvement strategies, rapidly developing VV tumor oncolytic immunotherapy. This article focuses on oncolytic vaccinia development and outlook in gastrointestinal cancer therapy, advantages when combined with other drugs to improve clinical survival, safety, and risk reduction for patients.