In this paper, we consider a system of delay differential equations that models the oncolytic virotherapy on solid tumours with the delay of viral infection in the presence of the innate immune response. We conduct qualitative and numerical analysis, and provide possible medical implications for our results. The system has four equilibrium solutions. Fixed point analysis indicates that increasing the burst size and infection rate of the viruses has positive contribution to the therapy. However, increasing the immune killing infection rate, the immune stimulation rate, or the immune killing virus rate may lead the treatment failed. The viral infection time delay induces backward Hopf bifurcations, which means that the therapy may fail before time delay increases passing through a Hopf bifurcation. The parameter analysis also shows how saddle-node and Hopf bifurcations occur as viral burst size and other parameters vary, which yields further insights into the dynamics of the virotherapy.

在本文中，我们考虑了一个延迟微分方程系统，该系统模拟了在存在先天免疫反应的情况下，实体瘤的溶瘤病毒治疗与病毒感染的延迟。我们进行定性和数值分析，并为我们的结果提供可能的医学意义。该系统有四个平衡解。定点分析表明，增加病毒的爆发大小和感染率对治疗有积极的贡献。但是，提高免疫杀伤感染率、免疫刺激率或免疫杀伤病毒率可能导致治疗失败。病毒感染时间延迟会导致向后的 Hopf 分叉，这意味着在通过 Hopf 分叉的时间延迟增加之前治疗可能会失败。