Researchers Closer to Finding HIV Vaccine

Altering viral swarm may drive development of antibodies that could neutralize HIV strains.

The findings of a recent study has important implications for the design of a protective HIV vaccine.

The study describes how the changing viral swarm in an HIV-infected person can drive the generation of antibodies that may be able to neutralize HIV strains from across the world.

The development of a vaccine to combat HIV remains the best hope for ending the pandemic, the study noted.

For many years, researchers have reported the major challenge in vaccine development as being the inability to stimulate broadly neutralizing antibodies that are able to deal with the enormous variability of HIV.

These neutralizing antibodies that some infected people are naturally able to broadly produce often have unusual features and need to go through an extensive maturation process before acquiring breadth.

Studying these rarities to understand how such antibodies develop provides a unique opportunity for scientists to develop vaccine strategies.

Researchers studied a single female participant who developed potent broadly neutralizing antibodies through a variety of high tech approaches, including the isolation of monoclonal antibodies from single B-cells and ultra-deep sequencing of shifting viral populations over more than 3 years of infection.

Investigators were able to look back in time to identify the unique virus that bound the precursors of what would become broadly neutralizing antibodies, beginning the immune pathway to breadth.

“The study also showed how these early antibodies matured to become broadly neutralizing. As the HIV-swarm struggled to evade these potent early antibodies, it toggled through many mutations in its surface protein. This exposed the maturing antibodies to a diverse range of viruses within this single infected woman,” the researchers wrote. “Antibodies exposed to this high level of viral diversity in turn mutated to be able to tolerate variation, thus acquiring the ability to neutralize diverse global viruses.”

With further analysis, the scientists will be able to design vaccines that can jump start and then shape the maturation of broadly neutralizing antibodies in uninfected individuals, providing protection from HIV exposure.