Vaccinia virus-based vector against infectious diseases and tumors.

Vaccinia virus was used to prevent smallpox. After the World Health Organization declared smallpox extinct, vaccinia virus has been explored for the development of vaccines against a variety of infectious diseases. It also finds a new place in oncolytic therapy. Here we provide a brief review of the history, current status, and future prospect of vaccinia virus-based vaccine and oncolytic virus. New advancements, including a single vaccine targeting multiple viruses, strategies of arming vaccinia viruses to enhance anti-tumor activity, the promise and challenge of combining vaccinia-based virotherapy with immunotherapy, are discussed as special focus.