HQ Team
December 15, 2023: A new vaccine to aid the human body’s white cells to fight HIV infection may hold the key to protect people from acquiring the virus, according to a National Institute of Allergic and Infectious Diseases (NIAID) study.
HIV, as it enters the body, begins to damage the immune system by entering the white blood cells, called CD4+ T cells, that help coordinate the immune response to the pathogens.
In a majority of people, HIV continues to replicate and damage more and more CD4+ T cells unless controlled by antiretroviral therapy.
Researchers drew comparisons between the immune system activity of past HIV vaccine study participants and people with HIV who naturally keep the virus from replicating in the absence of antiretroviral therapy. The latter is called “long-term progressors” or “elite controllers.”
CD8+ T cells
Among “elite controllers, “the immune system appears to promptly recognize CD4+ cells with HIV and activate other immune cells called CD8+ T cells. CD8+ T cells destroy CD4+ cells with HIV, enabling the suppression of HIV in a person’s blood,” according to the study.
An effective HIV vaccine would provide durable protective immunity to HIV, or if initial defences are bypassed, to help control HIV in the body long term, as happens with “active controllers.”
Several preventive HIV vaccine candidates have been designed in clinical trials to stimulate CD8+ T-cell activity, though they do not prevent HIV acquisition or control viral replication.
“Understanding and addressing this lack of effect is a scientific priority of HIV vaccine research.”
‘Persist longer’
The NIAID falls under the National Institutes of Health, the US’s medical research agency, which includes 27 Institutes and centres and is a component of the US Department of Health and Human Services.
Future HIV vaccine candidates may be more successful if they include additional doses or persist longer in the body to stimulate the immune system further, the researchers wrote in the Science journal.
They also wrote that the potential of an HIV vaccine might be better judged by measuring how it affects CD8+ T-cell function and sensitivity in addition to just assessing the number of CD8+ T cells generated, which has been the usual practice.
