HIV Vaccine Candidate Shows Promise In Primate Trials

Researchers at Oregon Health & Science University’s Vaccine and Gene Therapy Institute announced the promising findings of their HIV vaccine study, on Sept. 11.

The study, conducted on the primate version of HIV, called Simian Immunodeficiency Virus ( SIV), which causes AIDS in primates, involved vaccinating the monkeys and then infecting them with SIV. The findings show that the  immune systems of 50 percent of the monkeys were able to completely eradicate the virus from the body through an elicited T-cell response.

“To date, HIV infection has only been cured in a very small number of highly-publicized but unusual clinical cases in which HIV-infected individuals were treated with anti-viral medicines very early after the onset of infection or received a stem cell transplant to combat cancer,” said Louis Picker, M.D., associate director of the OHSU Vaccine and Gene Therapy Institute. “This latest research suggests that certain immune responses elicited by a new vaccine may also have the ability to completely remove HIV from the body.”

Pickler’s method involves pairing SIV with a CMV (common virus carried by most of the population).

“Through this method we were able to teach the monkey’s body to better ‘prepare its defenses’ to combat the disease,” explained Picker. “Our vaccine mobilized a T-cell response that was able to overtake the SIV invaders in 50 percent of the cases treated. Moreover, in those cases with a positive response, our testing suggests SIV was banished from the host. We are hopeful that pairing our modified CMV vector with HIV will lead to a similar result in humans.”

The next step in the study will focus on why the vaccine was unsuccessful in the other half  of the monkeys and what can be done to manipulate the vaccine to elevate it’s effectiveness, and hopefully bring it up to the level to be a viable HIV vaccine candidate in human trials.

This research was funded by several grants from the National Institutes of Health, funding from the International AIDS Vaccine Initiative and a CAVD grant from the Bill & Melinda Gates Foundation.