• Time from baseline until reaching the primary endpoint, a composite of either a CD4 cell count ≤350 cells/mm3 measured on two consecutive occasions at least 1 month apart, or initiation of HAART for any reason, whichever occurs first. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  

• Annual rate of change in CD4 count, calculated as the slope of patients' CD4 count change / time [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Annual rate of change in the CD4 cell count percentage, calculated as the slope of the patient's CD4 count percentage change over time [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Log10 plasma HIV viral load [ Time Frame: 12, 24 and 36 months of follow-up ] [ Designated as safety issue: No ]
  
• Treatment-emergent adverse events and laboratory abnormalities [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  
• Frequency of episodes of HSV reactivations at any anatomic site [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  
• Proportion of microbiologically confirmed flares of HSV during the trial that are caused by laboratory-confirmed acyclovir-resistant HSV [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  

Highly active antiretroviral therapy (HAART) has drastically reduced the morbidity and mortality associated with HIV infection, and transformed HIV from an invariably fatal disease into a manageable, chronic condition.

However, the inconvenience, high cost, potential side effects, and significant risk of developing drug-resistant HIV associated with taking daily, lifelong HAART make the potential delay of HAART initiation an extremely desirable goal for HIV-infected individuals.

Suppression of herpes simplex virus (HSV)-2 co-infection may provide a novel therapeutic strategy for achieving this goal. HSV-2 is among the most common co-infections seen in persons infected with HIV, with rates of up to 52-95%. This co-infection is associated with increased blood levels of HIV, a major predictor of HIV disease progression, even when the person has no herpes symptoms. Medications such as valacyclovir that suppress herpes can also decrease blood levels of HIV, but the potential long-term clinical benefits of this drug have not been adequately studied. It is thus hypothesized that valacyclovir could slow HIV disease progression and prolong the period of time before a co-infected person needs to initiate HAART. This research has been designed to answer this important question through a randomized, placebo-controlled, multi-centre clinical trial.