Given that the majority of infected CD4+ T cells in vivo carry replication-defective HIV, longitudinal measurements of the frequency of cells carrying replication-competent HIV along with other quantitative virologic parameters, such as levels of plasma viremia and cell-associated viral nucleic acid, can provide critical insight into the dynamics of the persistent viral reservoirs. Information related to HIV pathogenesis and the feasibility of eradicating the virus in infected individuals receiving ART in combination with novel therapeutic agents can also be gained from these analyses.