Antiretrovirals and Immune-Based Therapies


To date, scientists have not been able to find a cure for HIV. What has been discovered are drugs that put the virus on hold, offering many people longer, healthier lives. These drugs, called antiretrovirals (ARVs), also bring a variety of side effects some of which are difficult to live with and get worse over the years. Unfortunately, antiretroviral drugs can't cure HIV -- if you stop using them the virus comes back.

HIV is like herpes -- you can control it, but not get rid of it. Because of this, HIV scientists and activists are looking at a new goal for therapy -- how to get the body to control HIV without antiretroviral drugs.

ARVs and IBTs

A healthy immune system will get rid of or control most viruses by itself. When the immune system cannot do this alone, one way to help is to use chemicals that kill, weaken or stop viruses from making more viruses. In the case of HIV these drugs are called antiretrovirals because HIV is a "retrovirus."

Another way to help the body fight a virus is to boost the body's immune system. When scientists develop a therapy that helps the immune system fight a disease, we call it an "immune based therapy" or IBT.

Why We Need IBTs

We need immune-based therapies because antiretrovirals are not good enough. Antiretrovirals are great drugs, but they must be taken forever, on time, all the time. If you miss doses, they can stop working. And then there are the side effects.

Some antiretrovirals make so much fat in your blood doctors are concerned that in the long run the drugs will cause heart attacks. Others antiretrovirals cause problems with your emotions or disturb your sleep with vivid nightmares. Some run the risk of allergic reactions that can be deadly. Many are very hard on the liver. Other antiretrovirals give you lipodystrophy -- making faces and buttocks skinny and bellies and breasts fat.

In addition to side effects, no one knows if the drugs can keep the virus down for a lifetime. And antiretrovirals are very expensive.

These are the reasons scientists are looking at immune-based therapies for a less toxic, cost effective alternative.

What Kinds of Immune-Based Therapies Are Being Studied?

All immune-based therapies try to boost the immune system -- allowing your body to fight HIV more efficiently. Several immune-based therapies are being studied. Immune-based therapies vaccines are being tested to see if they can boost the immune system's ability to fight HIV.

Three vaccines have had some success. One is being studied in France, another one, called Remune, was tested in Spain and Merck is testing its version in the U.S. this year. It is clear, vaccines will play some role in helping us fight HIV.

Another effort going on is the use of certain chemicals the body produces and helps cells fight harder like IL-2 and IL-7. These chemicals are called cytokines. There is hope cytokines might help the body get rid of HIV altogether. The U.S. government is working on these studies.

In addition, antibodies have been discovered that help the body suppress HIV without drugs. These antibodies have been tested successfully in monkeys. If they work in people, long drug holidays may be possible. Why is this important? By giving people a "holiday" from taking their antiretroviral therapy, the body gets time to recover from drug toxicities.

Also, a very interesting extract taken from a cow, from a gland called the thymus, is being developed that looks like it helps the body get rid of a lot of HIV. This extract is being called thymus nuclear proteins or by it's initials: TNP.


Thymus nuclear proteins used in studies of HIV were developed by Viral Genetics, a small California biotech firm. They call their immune-based therapy "VGV-1."

An article about the viral genetics thymus extract was published in the journal HIV and AIDS Review in August of 2004. It explains that ten HIV-positive volunteers were given VGV-1 twice a week for two months along with their antiretroviral drugs. The volunteers were studied for six months. The volunteers had reportedly been failing their antiretroviral drugs and were on their second or third regimen.

Before these volunteers started taking VGV-1, they had quite a bit of virus. By three months, half the volunteers responded to VGV-1 and had undetectable amounts of virus. By six months, they had over 90% drop in the amount of virus. Most importantly this was months after these volunteers had stopped using VGV-1.

It is important to notice that before taking this version of thymus nuclear proteins, their antiviral cocktails were failing.

How Does TNP Work?

No one is sure.

It is known that thymus nuclear proteins sticks to a very important part of HIV that might stop HIV from getting into a cell. Or possibly thymus nuclear proteins get the immune system to kill off infected cells, the manufacturing plants for more HIV. More study is needed to understand why thymus nuclear proteins work.

Thymus nuclear proteins work MONTHS after you stop using it. This means it does something to the immune system to help it fight HIV better.

VGV-1 will be used in a large study in South Africa this year. Results will be known by this fall. If the results are the same as the results so far, it might well be the first immune-based therapy to stop HIV.

The Future

Vaccines might prevent millions from getting HIV in the first place. Antibodies can protect babies from getting HIV from infected mothers. Immune-based therapies make it possible to think of a future without toxic drugs. Immune-based therapies are the only hope for a world without AIDS.