Oncolytic virotherapy (OVT) is an extremely effective strategy that can simultaneously target multiple features of the suppressive tumour microenvironment (TME) in cancer and sensitize the tumours to other forms of immune or traditional therapeutics. My research focuses on Vaccinia virus (VACV), which is a particularly strong candidate OVT as it has a number of inherent features that render it superior to others, including: a lack of requirement for a specific surface receptor; a large insert capacity; a rapid, cytoplasmic lifecycle; the ability to replicate in hypoxic environments; the induction of immunogenic cell death pathways; and an ability to induce vascular collapse within the TME.