New research suggests that the earliest immune response to HIV may leave signals in blood that help predict whether a person later develops broadly neutralizing antibodies.
Broadly neutralizing antibodies are a major target in HIV vaccine research because they can block many different strains of the virus. Only a minority of people living with HIV develop them naturally, and scientists are trying to understand what immune pathways make that response possible.
The study, published in PLOS Pathogens and involving researchers from the University of Gothenburg and international collaborators, used cell-free RNA and DNA in blood plasma. This approach can capture immune activity, viral genetic variation, and traces of other microbes from the same blood sample.
Researchers analyzed 42 blood samples from 14 women in South Africa who were followed from before HIV infection through the first years after infection, before treatment began. They compared people who later developed broadly neutralizing antibodies with those who did not. The group that later developed those antibodies showed a distinct early pattern of immune activation, including genes involved in detecting virus-infected cells.
The findings are associations, not proof of cause. The study was also small, so larger studies are needed. Even so, the work gives vaccine researchers useful clues about the biology they may need to reproduce safely with vaccination. It also shows how blood-based genetic analysis can reveal the early host and microbial environment around HIV infection.