 1. Patients in Cohort I - Recently diagnosed will receive combination antiretroviral therapy designed to reduce the plasma viral load as quickly as possible, hence the rationale for the preferred inclusion of raltegravir, an integrase inhibitor. Both cohorts will have been treated in PHI, which may restrict the size of the reservoir compared with people initiating ART in later stages of HIV infection. Cohort II - Previously diagnosed participants are screened the same as Cohort I and are maintained on ART throughout the study. The ART regimen is preferably a combination that includes raltegravir, as hypothetically, if vorinostat induced viral transcription an integrase inhibitor may protect uninfected cells. However, there is no evidence to support this hypothesis and the key inclusion criteria must be the continuation of a virally suppressive ART regimen throughout the study. 