Researchers at the Duke Human Vaccine Institute have made a major breakthrough in developing an HIV vaccine. For the first time, they successfully induced broadly neutralizing antibodies (bnAbs) against HIV through vaccination. These antibodies can neutralize various strains of the virus, which is a crucial step toward an effective HIV vaccine.
Their findings, published in the journal Cell, show that it is possible to create these important antibodies through vaccination. The experimental vaccine targets a stable area on HIV’s outer envelope called the membrane proximal external region (MPER). This area stays consistent even as the virus mutates, making it a good target for antibodies to block infection.
Dr. Barton F. Haynes, director of the Duke Human Vaccine Institute, explained that this work demonstrates the possibility of inducing these antibodies with immunizations, even for the toughest strains of HIV. While they have not achieved a complete solution yet, the path forward is now clearer.
In a phase 1 clinical trial, 20 healthy, HIV-negative people received two or three doses of the experimental vaccine. Remarkably, after just two doses, the vaccine triggered a 95% serum response rate and a 100% blood CD4+ T-cell response rate, indicating strong immune activation. Most importantly, bnAbs were induced within weeks, a process that usually takes years following natural HIV infection.
Lead author Dr. Wilton Williams expressed excitement over the rapid emergence of neutralizing antibodies. However, the trial was paused due to a non-life-threatening allergic reaction in one participant, likely caused by an additive. Despite this, the researchers found other promising features, such as key immune cells staying in a developmental state that allowed them to keep evolving alongside the virus.
The researchers know more work is needed to create a stronger response and target other parts of the virus envelope. But they are optimistic. Dr. Haynes emphasized the goal of targeting all vulnerable sites on the virus envelope to prevent it from escaping.
This ability to quickly induce bnAbs through vaccination is a significant milestone in the long search for an effective HIV vaccine. It gives hope for developing a multi-component vaccine that can neutralize various HIV strains.
