Combination Vaccine Therapy Shows Promise for HIV Remission

A research team led by Beth Israel Deaconess Medical Center (BIDMC) in collaboration with Walter Reed Army Institute of Research (WRAIR), Janssen Vaccines and Prevention has combined an experimental vaccine with immune stimulant to help HIV remission in patients.// The study findings was published online in the journal Nature.

In animal studies the combination of an experimental vaccine with immune stimulant decreased the levels of viral DNA in lymph nodes and the blood. This was found to improve viral suppression and delay rebound following anti-retroviral therapy.

Dan Barouch, MD, PhD, director of the center for virology and vaccine research at BIDMC said, "The objective of our study was to identify a functional cure for HIV - not to eradicate the virus, but to control it without the need for ART."

"Current antiretroviral drugs, although they're lifesaving, do not cure HIV. They merely hold it in check. We are trying to develop strategies to achieve ART-free, long-term viral suppression."

Human Immunodeficiency virus when left untreated may cause AIDS. HIV is capable of attacking the immune system and kills the majority of the infected immune cells leaving behind few dormant cells. Scientists believe that these dormant HIV cells are the reason why the infection cannot be cured completely and are working to eradicate the virus from the body.

Barouch said,"We reasoned that if we can activate the immune cells that might harbor the virus, then the vaccine-induced immune responses might perform better seeking them out and destroying them."

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"Indeed, we saw the best results when we combined the vaccine together with the innate immune stimulant."

In the two year research study, the viral load of 36 rhesus monkeys which were infected with simian immunodeficiency virus was monitored. Simian immunodeficiency virus (SIV) is a similar type of HIV virus which is often found to affect non-human primates.

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Suppressive anti-retroviral drugs were administered to the monkeys for 6 months. After which experimental vaccines like adenovirus serotype 26 vector vaccine or an MVA vector vaccine was given alone or an immune stimulant (TLR-7) was administered alone or a combination of the experimental vaccine with immune stimulant was given together. The control group of monkeys did not receive any active treatment.

Col. Nelson Michael, director of MHRP found the combination of AD26/MVA vaccination along with TLR7 stimulation to be effective in HIV remission than using them alone.

This would show a striking response in the viral load which affects the disease progression. Viral load is the number of virus particles present in one milliliter of the blood.

Experimental vaccines were found to induce an immune response on the number of immune cells that are generated and in the number of places where the virus can target.

The study findings found that the combination therapy of an experimental vaccine along with immune stimulant to be effective in reducing the plasma RNA levels as well as showed a 2.5 fold delay of viral rebound in HIV remission when compared to the control group. All the animals showed a decrease in the viral load while only three out of the nine animals showed no trace of the virus in the body.

The author concluded that the findings would help provide new hope for HIV remission.



Source-Medindia