Trial Will Examine Novel HIV Vaccine Candidate Designed to Stimulate Immune Response

The International AIDS Vaccine Initiative (IAVI) has announced the launch of a phase 1 clinical trial testing the safety and immunogenicity of an HIV vaccine candidate designed to stimulate an immune response against HIV. According to IAVI, the novel vaccine—eOD-GT8 60mer—stimulates the immune system to initiate a key first step in the generation of potent proteins, known as broadly neutralizing antibodies (bNAbs).

The announcement comes a month after a report concluded that the current drug pipeline is unlikely to produce any highly effective vaccines for HIV, tuberculosis, or malaria, due to a lack in funding.

“Researchers widely agree that a vaccine that induces bNAbs will likely be the best way to confer durable protection against the virus,” according to the press release. “bNABs are desirable because in laboratory experiments, they are effective against many of the genetically diverse strains of HIV, and in animal studies, they block infection of a virus similar to HIV.”

Previous research has yielded understanding of the structure of HIV’s outermost envelope protein, which is the target of all bNAbs. During large studies of patients with HIV, researchers have been able to isolate and characterize many bNAbs that develop naturally, but rarely, during the course of HIV infection, and have identified where they bind to the virus.

Using these sites of vulnerability, researchers designed vaccine immunogens, known as a structure-based vaccine approach. The candidate vaccine is based on one of the sites targeted by bNAbs and is the first to enter clinical trial that is designed using the structure-based vaccine approach. It is also the first in a sequence of engineered vaccine candidates the researchers are working on.

The trial will enroll 48 healthy adult volunteers who will receive 2 doses of the vaccine, along with the AS01_B¹ adjuvant to enhance immune response, or placebo spaced 2 months apart. The trial will take place at 2 sites: George Washington University in Washington, DC, and the Fred Hutchinson Cancer Research Center in Seattle, Washington. Results of the trial are expected late next year.

“This is a big moment, not just for HIV vaccines, but for vaccine science as a whole," Dennis Burton, PhD, scientific director, Neutralizing Antibody Center, and chair of the department of immunology and microbiology at Scripps Research, said in a statement. “This trial is going to tell us how much control we have over the immune responses induced by a targeted vaccine candidate. If this type of vaccine engineering is successful, it can be applied more broadly, bringing about a new day in vaccinology.”

The applicability of this research to broader health fields would not be the first time HIV research has had positive impacts across other medical fields. In September, experts from the National Institutes of Health's Institute of Allergy and Infectious Diseases reported that years of HIV research has translated into advances outside the HIV field, including in immunology and oncology.