TUESDAY, SEPTEMBER 27, 2016

HIV vaccine trial begins in South Africa

A new HIV vaccine trial has begun in South Africa. | Courtesy of niaid.nih.gov

South Africa is hosting a new trial that will determine the safety and efficacy of an investigational HIV vaccine regimen.

The study is based on a similar regimen (RV144) that recently proved successful when it was tested in a U.S. military HIV research program based in Thailand.

In comparison with the RV144 regimen, HVTN 100 has been modified to provide improved protection. Scientists intend for it to prevent the most common HIV subtype in South Africa.

The RV144 study showed that the vaccine had a 60 percent efficacy after one year, but that dropped to 31.2 percent within the 3.5 years of receiving the vaccine.

Researchers will conduct the HVTN 100 study to determine whether the modified vaccine has improved the duration and breadth of the vaccine’s protection.

HVTN 100 regimen contains two experimental vaccines: a gp120 protein subunit vaccine combined with an adjuvant and a canarypox-based vaccine named ALVAC-HIV. Both of these vaccines have been improved from the RV144 version to specifically treat HIV subtype C, which is the prevalent strain of HIV in South Africa. The new adjuvant, which was not used in RV144, was added in an effort to create a stronger immune response.

The study involves 252 HIV-uninfected heterosexuals between the ages of 18 and 40. The HVTN subjects will be monitored for their safety, and the researchers will also instruct them on the best ways to prevent contracting HIV.

Scientists will administer eight injections in each participant throughout the first year of the study. The subjects will receive random assignments to the placebo (42 participants) or the regimen (210 participants) groups.

The vaccine regimen requires that patients receive booster shots each year to maintain the vaccine’s effectiveness. The study is expected to be completed in approximately two years.

“Our country is helping lead the way in HIV prevention research," Glenda Gray, president of the South African Medical Research Council and HVTN co-principal investigator, said. "A safe and effective vaccine is our best hope for stopping new HIV infections and protecting the health of our communities.”