Phase 1 Trial Will Test Safety of Vaccine for HIV Prevention

The safety and tolerability of a vaccine that may have the potential to prevent HIV infection will be assessed in a phase 1 clinical trial.

Researchers from the University of Massachusetts Medical School will test the vaccine’s safety as well as its ability to create an immune response against HIV. The study is largely a result of research from Shan Lu, MD, PhD, professor of medicine and biochemistry and molecular pharmacology, who has worked on the development of DNA vaccines. DNA vaccines—vaccines that use synthetic DNA to create HIV-specific immune response after vaccination—are a novel approach, depending on using limited DNA sequences from HIV as an initial priming immunization for the immune response. The priming is followed by a boost with a protein vaccine matching the proteins made by the DNA.

In order to enhance immune response, the vaccine is used in combination with the adjuvant GLA-SE, a synthetic lipid A derivative and selective toll-like receptor 4 agonist. This treatment approach will be tested among one group of study participants while another receives the DNA and protein vaccines simultaneously. Both groups will be tested over 6 to 12 months in the double-blind study.

Using both DNA and protein vaccines, whether sequentially or simultaneously, activates both antibody- and cell-mediated immune responses, which may be necessary for an effective HIV vaccine, according to the researchers. The vaccines in the trial include 5 DNA components and 4 proteins.

“The immune system uses B-cells to produce the antibodies that fight viral invaders,” said Lu. “The HIV DNA bits drag the B-cells out of sleep. We then expose the B-cells to specific HIV proteins, which are some of the most susceptible parts of the virus, so they can start producing antibodies that target these vulnerabilities. The prime and boost combination gives the immune system the added jolt it needs to produce antibodies to fight the virus.”

The researchers will enroll participants from 4 locations: the University of Pennsylvania, the University of Alabama-Birmingham, Care Western Reserve University, and Fenway Health. Those participating in the trial will be healthy volunteers who are at low risk for HIV exposure for determining the safety and tolerability of the vaccine, as well as the immune response from the vaccine. The researchers noted that although this initial study is an exciting step, it will not evaluate whether the vaccine strategy protects the vaccinated subjects from becoming infected with HIV.

The study is being supported by the National Institutes of Health.