In a Subset of Subjects on Highly Active Antiretroviral Therapy, Human Immunodeficiency Virus Type 1 RNA in Plasma Decays from 50 to <5 Copies per Milliliter, with a Half-Life of 6 Months

Abstract
Three of five virally suppressed human immunodeficiency virus type I (HIV-1)-infected patients treated with highly active antiretroviral therapy and followed intensively with a supersensitive reverse transcriptase PCR assay with a lower limit of quantitation of 5 copies/ml showed statistically significant viral load decays below 50 copies/ml, with half-lives of 5 to 8 months and a mean of 6 months. This range of half-lives is consistent with the estimated half-life of the latent HIV-1 reservoir in the peripheral blood. Those patients without decay of viral load in plasma may have significant cryptic HIV-1 residual replication.