June marks the 40th anniversary of the first scientific report describing pneumocystis pneumonia, which was later known as Acquired Immune Deficiency Syndrome (AIDS). More than 32 million people have died worldwide from AIDS and 38 million people are living with HIV, the virus that causes AIDS, according to the Centers for Disease Control and Prevention.
“The last 40 years of the HIV epidemic have deepened us in society, science, medicine and the socioeconomic impacts of diseases on communities and countries. Forty years ago it was the first report. However, we didn’t even do it “You know what the causative agent was,” says Dr. Stacey Rizza, an infectious disease doctor at the Mayo Clinic and an HIV researcher.
Unfortunately, the AIDS crisis of the 1980s was permeated with misinformation and discrimination, especially against gay men, disproportionately affected by the disease. Much progress has been made since then, but much work remains to be done.
“The diagnosis of HIV / AIDS has a different meaning than it did just two decades ago,” says Dr. Rizza. “It’s a whole new world, and for those of us who are a little older and started treating HIV in the 90’s and I saw this world, it was tragic. We saw wonderful people who were brave and fought their virus“But unfortunately we couldn’t prevent the virus from spreading.”
HIV is a sexually transmitted infection transmitted by contact with infected blood, semen, or vaginal fluids. The virus can also be spread by sharing needles and syringes for medicines, and less commonly from mother to child.
In these questions and answers, Dr. Rizza provides some insight into understanding the research and why AIDS is such a difficult disease to cure:
Q. What did the first investigations find?
A. Because of the truly dedicated innovative science, in a few years, the scientific community discovered that AIDS was due to HIV. It then took a few years to figure out how to test this virus. Several years later, the scientific community was able to quantify the amount of virus that was in a person’s blood. All this time, truly innovative research on how the virus replicates and how the immune system responds to the virus has allowed biological pharmacy companies to develop what we call antiretroviral drugs or drugs to slow viral replication.
Q. How has medication to treat HIV evolved?
A. The first drug approved for HIV was in 1987, which was AZT (now known as zidovudine). At the time, it was the fastest drug ever approved by the FDA (Food and Drug Administration) and initiated the fast-track mechanism through the FDA.
Then, several other drugs of the same class were approved in the early 1990s. In late 1995, well into early 1996, the first HIV protease inhibitors were approved. At that time, it was possible to combine three different drugs from two different classes and completely suppress HIV replication.
In the last 20 years, we have gone from people taking various medications with many side effects to [how] now many of my HIV patients take only one pill a day. It is a combination of medications co-formulated into an extremely well tolerated daily pill that completely suppresses your virus. We know it does not eliminate the virus. If they stopped taking this medicine, the virus would return. But now we have a handful of people in the world who have been what we call functionally cured of HIV, that is, who have gone through some research protocols that removed the reservoir of HIV in their body.
The new drugs are so effective in people who have completely suppressed the virus that many only need to use two drugs to maintain HIV treatment and control. New research is investigating ways to supply medications differently, such as a shot that lasts several months, or maybe someday, even implantable drug delivery mechanisms so people don’t have to take the pill every day. . It is very exciting that HIV therapy is going in this direction.
Q. Why is there no cure for HIV?
A. The reason it is so difficult to cure HIV is that once HIV infects a person’s body, it integrates into the host genome of various cell types. These cells hide in any of the lymphoid tissues, such as the lymph nodes, liver, and spleen. And they are there like what we call “latent” or “hidden,” as long as the person is in HIV therapy. Whenever a virus leaves a cell, it takes over HIV therapy. But if the infected person stops HIV therapy, this latent virus will return. To cure HIV, you need to get rid of those viruses that hide in the cells or that latent viral deposit, which is the term. There are many ways to consider reservoir removal.
Q. Where is the research now?
A. One of the most popular ways that has been investigated is something called — and there are many different terms for it—: “first, hit and kill” or “kick and kill,” which is essentially to give drugs that first wake the virus from latency and then find ways to make the cells that have the virus susceptible to death. When the virus is awake and the cell is susceptible to death, it kills itself but does not kill any other cells in the body.
Basically, it specifically targets HIV-infected cells and removes them without hurting anything else. This new science is exciting. It’s getting closer and closer to understanding how to do it effectively. And if you can do it with oral medications instead of smart therapies like gene therapy or bone marrow transplantation, it’s scalable in large parts of the world and you can touch millions of people that way. This is where we work on how to wake up these hidden cells, how to make them sensitive to death, and how to target only HIV-infected cells.
Q. Will we see an HIV vaccine?
A. HIV has been a very difficult vaccine to develop. In the world of viruses, vaccines fall into one of three cubes. They fall into the bucket where they respond to vaccine-induced antibodies, and the vaccines are excellent. These viruses include polio, mumps and luck for us, SARS-CoV-2. Then we have the second category, such as the flu vaccine, which is about 60% effective. It certainly saves lives and makes a difference, but it’s not perfect. And then we have the third deposit, which frankly is the vast majority of viruses that infect humans. And HIV falls into this category, in which simply forming an antibody against the virus is not suitable for preventing infection. You have to do very sophisticated engineering to induce T cell effects as well as innate effects and antibody effects. Even then, it is sometimes very difficult to decide which part of the virus you want to target. After decades, and billions of dollars in research, we are still not there for HIV. There have been many approaches to how to do this science. There are many different scientific distribution mechanisms, many different areas of targeted viruses, many different parts of the targeted immune system, and so far none of them have been effective in preventing HIV infection.
Q. What should happen next?
A. We still need to slow down the number of infected people through good public health measures and good education to stop the HIV epidemic. We still need to get more people infected with therapy.
We know we can do it with public health measures. But we also need to find out more about how we eliminate this reservoir and get people cured of the virus in a simple and effective way so we can cure more people. And the last big hurdle we have is to develop an effective vaccine. We do not yet have any vaccine that can prevent infection, a preventive vaccine or a therapeutic vaccine where you give it to people who already have the virus to help them control the infection. There’s been a lot of research going on, but we’re not there yet.
© 2021 Clínica Mayo News Network. Distributed by Tribune Content Agency, LLC.
Citation: 40 years of HIV / AIDS: will the epidemic end? (2021, June 15), retrieved June 16, 2021 at https://medicalxpress.com/news/2021-06-years-hivaids-epidemic.html
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