VIVA trial: Vitamin D in HIV latency

The current standard treatment for people living with HIV is a combination of drugs known as antiretroviral therapy (or ART). This treatment stops HIV from replicating within CD4+ T cells, an important component of the immune system, and allows recovery of these cells. Although ART allows people living with HIV to have near normal life expectancy, ART is not a cure for HIV as the virus lies silently in some CD4+ T cells in the body and can start replicating again if ART is stopped. Therefore, people living with HIV need to stay on ART for the rest of their lives.

There is a specific type of CD4+ T cell, known as a Th17 cell, that is highly vulnerable to HIV. Th17 cells are found in high concentrations in the gut wall where they are normally involved in fighting bacteria and fungi found within the gut. When people get infected with HIV, these Th17 cells get infected and killed very quickly. The gut then becomes inflamed and bacteria can invade the gut wall. New Th17 cells may then migrate from the blood to the gut but become infected with HIV and die. The number of Th17 cells and gut inflammation improve on ART but gut inflammation does not resolve completely. Ongoing mild inflammation in the gut may be one reason why HIV is able to persist despite ART.

Vitamin D has been shown to reduce the number of these susceptible Th17 cells in HIV uninfected humans. Vitamin D also strengthens the lining of the gut wall in mice, thereby reducing gut inflammation, and it can make bacteria in the human gut less dangerous. Additionally, it can activate HIV production from its hiding place in cells in the lab. In the body, this effect may allow the immune system to recognise those cells as infected and kill them. Taking antiretroviral therapy would prevent new cells from becoming infected by this newly produced HIV.

The purpose of the VIVA trial is to determine whether taking 6 months of high dose vitamin D (10,000 international units daily) in addition to usual ART can reduce the number of Th17 cells, reduce inflammation and gut leakiness, improve the immune response to HIV and reduce the amount of HIV hiding in the body. There will also be a 3 month follow-up phase to determine if any effect seen at the 6 month mark persists after stopping vitamin D. Participants will have a random 1 in 2 chance of receiving high dose vitamin D versus placebo and will not find out which treatment they have taken until the study is completed.

If vitamin D reduces the amount of persistent HIV or reduces inflammation or leakiness of the gut, a larger study will be set up to see if the effects would allow individuals to stop ART safely. Please note that there is currently not enough evidence to suggest that vitamin D could contribute to an HIV cure and participants in the VIVA trial will be required to continue their ART throughout the study.

The VIVA study is currently recruiting at the Doherty Institute, Royal Melbourne Hospital, The Alfred and Melbourne Sexual Health Centre. If you live in Melbourne, have been on HIV treatment with an undetectable viral load for at least 3 years, have taken no vitamin D containing supplements in the last 6 months and are interested in participating in this important study, please call the Doherty Institute Clinical Research team on 1300 HIV CURE (1300 448 287) to express interest and find out more.

Study details

Study contact

Doherty Clinical Research on 1300 HIV CURE (1300 448 287)

ART clinical trial HIV latency research vitamin D