Table 1.

Definitions of the parameters used in the model

	Variable, parameter and description	Initial or default values
Variables
T	Uninfected CD4+ cell population size	1200 cells/μl
T*	Infected CD4+ helper cell population size	0
VI	concentration of infectious virus particles	10−6 copies/μl
VNI	concentration of non-infectious virus particles	0
Parameters
s	Generation rate for uninfected CD4+ T cell	15 μl−1 day−1
d	Death rate of uninfected CD4+ T cells	0.01 day−1
k	Infection rate for CD4+ T cells by virus	2.4 × 10−6 μl−1 day−1
δ	Death rate of infected CD4+ cells	0.35 day−1
λ	Number of free virus produced by lysing a CD4+ cell	3000 day−1
c	Death or clearance rate of free virus	3 day−1
ηRT	RTI drug efficacy	0.5–1
ηPI	PI drug efficacy	0.5–1