A Within-Host Virus Model with Periodic Multidrug Therapy.

This paper is devoted to the investigation of the effects of periodic drug treatment on a standard within-host virus model. We first introduce the basic reproduction ratio for the model, and then show that the infection free equilibrium is globally asymptotically stable, and the disease eventually disappears if $\mathcal{R}_{0} < 1$, while there exists at least one positive periodic state and the disease persists when $\mathcal{R}_{0}>1$. We also consider an optimization problem by shifting the phase of these drug efficacy functions. It turns out that shifting the phase can certainly affect the stability of the infection free steady state. A numerical study is performed to illustrate our analytic results. [ABSTRACT FROM AUTHOR]