Dynamical behaviour of a delay differential equation of Hepatitis B virus

In this paper, we investigate a class of virus dynamics model with intracellular delay and nonlinear infection rate of saturated functional response. The basic reproduction number R
₀
for the viral infection is derived, and the global dynamics behavior are completely determined by R
₀
. By constructing suitable Lyapunov functional and using LaSalle invariant principle for the delay differential equations, we find when R
₀
≤ 1, the infection-free equilibrium is globally asymptotically stable, and when R
₀
> 1, the infection equilibrium is also globally asymptotically stable.