If CD4 T cell trafficking is increased, but to a rate that is still below the critical threshold, the resulting infected cell number depends upon the balance between two effects: first any increase in incidence fueled by a net influx of susceptible cells into the drug sanctuaries (see S2 Text for discussion); and second, faster removal of infected cells from drug sanctuaries. If the trafficking rate is increased to a level just below the critical threshold, infected cell numbers decline to a new, lower equilibrium in the drug sanctuaries, but in the main compartment they increase (Fig 5B). Increasing the clearance of infected cells within drug sanctuaries acts synergistically with increased trafficking of cells out of drug sanctuaries.