title: Sustained and transient oscillations and chaos induced by delayed antiviral immune response in an immunosuppressive infection model.
abstract: 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: (i) a stable equilibrium can coexist with another stable equilibrium, and (ii) a stable equilibrium can coexist with a stable periodic solution.
authors.affiliation: Department of Mathematics and Statistics, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada.
authors.forename: Hongying
authors.initials: H
authors.lastname: Shu
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: James
authors.initials: J
authors.lastname: Watmough
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D003198:Computer Simulation; D006801:Humans; D018448:Models, Immunological; D019562:Viral Load / Q000276:immunology*; D014777:Virus Diseases / Q000188:drug therapy / Q000276:immunology*; D014780:Viruses / Q000276:immunology*
chemical_list: D000998:Antiviral Agents