About The Study

This study aimed to answer if oral valacyclovir 500mg twice daily can slow the rate of CD4 count decline and ultimately delay the need to start antiretroviral therapy (ART) in adults with HIV and infrequent recurrences of herpes, who are not currently needing nor taking ART. This study was designed to test the effectiveness of using of chronic suppressive valacyclovir as a therapeutic strategy used to delay the start of ART in HIV and herpes simplex virus type 1 and 2 (HSV-2, HSV-2) co-infected adults. At the time of study initiation, the side effects of ART were much more significant, meaning that strategies to decrease the need for ART was a common area of study.

Trial participants were randomly assigned to either a valacyclovir group or a placebo group. Both groups received one pill twice a day. Follow-up for all participants included standard-of-care medical assessments and blood tests for up to five years following study enrolment or until primary end-point was reached (e.g., the need to start ART).

This was a multi-centre, randomized, placebo-controlled trial recruiting 230 participants over two years at 15 sites across Canada, Brazil, and Argentina.

About The Disease

Herpes simplex virus is among the most common co-infections in individuals infected with HIV with prevalence rates of 52-95%. HSV-2 is associated with increased HIV-infection, disease progression and transmission. HSV-1 may also adversely impact on HIV.

Study Approach

Valacyclovir is a Health Canada approved, safe and well-tolerated HSV medication with over 10 years of public use. Anti-HSV medications, such as valacyclovir, are associated with decreased HIV viral loads yet the use of this treatment to slow the rate of CD4 count decline in HIV co-infected adults has not been adequately studied.

CTN 240 researchers hypothesized that valacyclovir in co-infected adults may slow the rate of HIV disease progression and the need to initiate HAART.


Final results for this study showed that valcyclovir was unsuccessful in slowing the decline in CD4 count and delaying the need for ART.

Principal Investigators

Here’s who is leading this study.

Can’t find what you’re looking for? Email ctninfo@hivnet.ubc.ca.

Participating Sites

Here’s where this study is being conducted.