Effect of time delays in an HIV virotherapy model with nonlinear incidence

In this paper, we propose a mathematical model for HIV infection with delays in cell infection and virus production. The model examines a viral therapy for controlling infections through recombining HIV with a genetically modified virus. For this model, we derive two biologically insightful quantities (reproduction numbers)R 0 andR z , and their threshold properties are discussed. WhenR 0 < 1 , the infection-free equilibriumE 0 is globally asymptotically stable. IfR 0 > 1 andR z < 1 , the single-infection equilibriumE s is globally asymptotically stable. WhenR z > 1 , there occurs the double-infection equilibriumE d , and there exists a constantR b such thatE d is asymptotically stable if1 < R z < R b . Some simulations are performed to support and complement the theoretical results.