In the last year, over 40 million people in the world were living with human immunodeficiency virus (HIV). In 2024, over a million were diagnosed with HIV and roughly 630,000 died due to HIV-related complications. HIV is a fatal virus that weakens the immune system by destroying necessary immune cells that protect the body from foreign pathogens. If left untreated, patients will lose enough immune cells and contract acquired immune deficiency syndrome (AIDS). The difference between HIV and AIDS is that AIDS is the late stage or advanced form of HIV. Consequently, AIDS is the state of a severely weakened immune system with an immune cell count below 200 cells/mm3 in the blood.
Standard treatment for HIV includes antiretroviral therapy (ART), which is a combination of daily medication. Unfortunately, ART does not cure HIV; however, it prolongs survival and allows patients to live healthy lives. If caught early enough, HIV patients have the potential to live high quality lives uninterrupted by medical complications. Remarkably, ART can also reduce the risk of transmitting the virus to others. Physicians are also prescribing pre-exposure prophylaxis (PrEP) to those that are at higher risk of contracting HIV. PrEP is a daily pill and significantly reduces an individual’s risk of HIV. In addition, it is recommended to always avoid unnecessary injections and use protection during sexual intercourse.
Scientists are currently working to develop better treatments and discover a way to completely cure HIV. A recent study in Nature, by Dr. David Collins and others, discovered why some patients with HIV respond to therapy and can safely wean off it. Additionally, these same patients seem to maintain control of the virus for the rest of their life. This new discovery provides insight into the mechanism behind HIV and can improve current standard-of-care treatment. Collins is an Instructor of Medicine at Harvard Medical School and a Principal Investigator at the Ragon Institute of Massachusetts General Hospital. His work focuses on immune cell response to HIV and how to improve treatment for HIV and AIDS.
Collins and his team analyzed blood samples of 12 patients who received a treatment called broadly neutralizing anti-HIV antibodies (bNAbs) and then stopped taking the medication. Researchers compared the samples of seven patients (among the 12) that controlled HIV after seven years to the other five that experienced viral recurrence. They found that specialized immune cells, known as CD8+ T cells, could proliferate and continue to eliminate the virus in patients that did not experience viral rebound. The bNAbs treatment was effective, but the quality of CD8+ T cells that were already present in patients predicted whether their immune systems would control viral spread or not.
The CD8+ T cells that recognized the virus and could proliferate were able to eliminate the infection and improve patient health. Scientists are optimistic they can elicit similar responses in all patients with HIV that receive bNAbs. This new treatment approach is a breakthrough in viral therapy and has the potential to be used to design beneficial HIV combination therapies.
Study, Nature, David Collins, Harvard Medical School, Ragon Institute, Massachusetts General Hospital