  We study the global stability of a class of models for in-vivo virus
dynamics, that take into account the CTL immune response and display antigenic
variation. This class includes a number of models that have been extensively
used to model HIV dynamics. We show that models in this class are globally
asymptotically stable, under mild hypothesis, by using appropriate Lyapunov
functions. We also characterise the stable equilibrium points for the entire
biologically relevant parameter range. As a byproduct, we are able to determine
what is the diversity of the persistent strains.
