12月19号 下午 2：00-3：00 报告
地点：创新研究院数学中心813
报告人：陕西师范大学 舒洪英 教授
题目：Boosting immunity by antiviral drug therapy
摘要：Sustained and transient oscillations are frequently observed in clinical data for immune responses in viral infections such as human immunodeficiency virus, hepatitis B virus, and hepatitis C virus. To account for these oscillations, we incorporate the time lag needed for the expansion of immune cells into an immunosuppressive infection model. It is shown that the delayed antiviral immune response can induce sustained periodic oscillations, transient oscillations and even sustained aperiodic oscillations (chaos). Both local and global Hopf bifurcation theorems are applied to show the existence of periodic solutions, which are illustrated by bifurcation diagrams and numerical simulations. Two types of bistability are shown to be possible. We further numerically explored the joint impacts of the duration of therapy, the efficacy of the drugs and the time lag in immune expansion on immunity boosting for a single phase of therapy. Our findings reveal that a single phase of therapy can establish sustained immunity if the therapy is stopped in a suitable range of timing and large time lag in the expansion of immune cells and too strong or too weak therapy would lead to a failure in immunity boosting. Our findings may provide some insights on designing efficient and rational therapy strategies in boosting sustained immunity.