vaccineA new study helps AIDS vaccine researchers further understand how HIV interacts with its host, and how some people naturally produce antibodies against the virus’ many variants. The study, authored by researchers from the International AIDS Vaccine Initiative (IAVI) and partners, was published on 14 January in PLOS Pathogens.

HIV is the most challenging virus humankind has ever faced. It changes very rapidly, varies by region and escapes the human immune system’s responses. A few of the people who contract HIV naturally produce powerful antibodies that can neutralize many of the virus’ variants. IAVI and many fellow researchers are working to design and develop a vaccine that can mimic and accelerate this lengthy process.

The new study suggests that both viral and host factors may be critical for the development of such broadly neutralizing antibodies (bNAbs), and that one “supersite” on HIV’s envelope protein may be a particularly favourable target for vaccine design.

This research utilized samples from 439 newly infected volunteers in Protocol C, a large observational study by IAVI and partners in Eastern and South Africa supported by the United States Agency for International Development (USAID). About 15% developed bNAb responses, on average 3 years after infection.

Gender, age and geographical origin appeared to have no influence on the development of bNAbs. However, the study showed that broad neutralization was associated with high viral load, low levels of particular immune cells, infection with one particular HIV subtype, and the presence of a particular gene in the host.

“These findings add to the important lessons that AIDS vaccine science continues to learn from large observational studies like Protocol C,” said Mark Feinberg, IAVI President and CEO. “The volunteers who participate in these studies are critical and valued partners in the effort to design a safe and effective AIDS vaccine.”