Fig. 1

Phasic decline of viremia due to death of HIV-1 infected cells following ART. The multiphasic decay in plasma viremia following initiation of ART has been attributed to the varying half-life of infected cells. Death of productively infected activated CD4+ T cells with a half-life of 1–2 days contributes to the first phase of decline. The slower second phase during which viremia becomes undetectable is contributed to by cells with a half-life in the order of weeks. The cells contributing to the second phase have not been conclusively identified. This is followed by the third phase of decline, characterized by undetectable steady viremia due to infected resting memory CD4+ T cells with a half-life of 44 months