This Demonstration implements the mathematical model of HIV infection as described in [1]. The notation used here, which differs from that of [1], is as follows:

is the number of uninfected T cells.

is the number of infected T cells.

is the number of free virus particles.

Uninfected T cells are produced at a rate .

In the absence of a virus, uninfected T cells die at a rate .

Uninfected T cells turn into infected T cells at a rate .

Infected T cells die at a rate , releasing virus particles each time an infected T cell dies.

Finally, free virus particles are eliminated by the body at a rate .