Researchers identify antibody that neutralizes 98% of HIV strains

© Athit Perawongmetha
An antibody from an HIV-infected person has successfully neutralized 98 percent of HIV isolates tested, including the lion’s share of strains resistant to other antibodies of the same class, US scientists have found.

The striking efficiency of the powerful antibody, named N6, makes it an ideal candidate for further research to treat or prevent HIV infection, scientists from the National Institutes of Health, the largest biomedical research agency in the world, have stated.

Scientists scrutinized the evolution of N6 over time to understand how exactly it managed to develop the ability to potently neutralize the majority of HIV strains.

Researchers say that identifying broadly neutralizing antibodies against HIV has been a real challenge because the virus rapidly changes its surface proteins to avoid recognition by the immune system.

In 2010, scientists at National Institute of Allergies and Infectious Diseases (NIAID’s) Vaccine Research Center (VRC) discovered an antibody called VRC01 that can stop up to 90 percent of HIV strains from infecting human cells.

“Like VRC01, N6 blocks infection by binding to a part of the HIV envelope called the CD4 binding site, preventing the virus from attaching itself to immune cells,” researchers said in a press release published on Tuesday.

Findings from the latest study showed that N6 developed a “unique mode of binding that depends less on a variable area of the HIV envelope known as the V5 region and focuses more on conserved regions, which change relatively little among HIV strains. This allows N6 to tolerate changes in the HIV envelope, including the attachment of sugars in the V5 region, a major mechanism by which HIV develops resistance to other VRC01-class antibodies.”

The new findings suggest that N6 could pose advantages over VRC01, researchers noted, adding that due to its potency, N6 may offer "stronger and more durable prevention and treatment benefits, and researchers may be able to administer it subcutaneously (into the fat under the skin) rather than intravenously."

According to UNAIDS, there were approximately 36.7 million people worldwide living with HIV/AIDS at the end of 2015.  Of these, 1.8 million were children younger than 15 years old. The vast majority of people living with HIV are from low- and middle-income countries.

The WHO estimated that currently only some 54 percent of people with HIV know their status.