Experimental HIV Vaccine Could Boost HAART Efficacy
(HealthDay News) — Preliminary research suggests that an HIV vaccine in development can ramp up the body's immune system, boosting the response to highly-active antiretroviral therapy (HAART). The study findings were published online April 29 in Retrovirology.
Barbara Ensoli, MD, PhD, director of the National AIDS Center at the National Institute of Health in Rome, and colleagues conducted a phase II clinical trial that injected 168 HIV-infected patients with the biologically active HIV-1 vaccine containing either 7.5µg or 30µg of the Tat protein three to five times monthly for 48 weeks. The patients also continued on HAART. The researchers tracked the patients for up to 144 weeks, or nearly three years.
The researchers found that the vaccine was safe and well tolerated, inducing anti-Tat antibodies in 79% of patients, with the highest frequency and durability in the Tat 30µg groups when given three times. Vaccination also promoted a durable and significant restoration of T, B, natural killer cells, and CD4+ and CD8+ central memory subsets. A significant reduction of blood proviral DNA was seen after week 72, and reached a predicted 70% decay after three years from vaccination with a half-life of 88 weeks.
"Anti-Tat immune responses are needed to restore immune homeostasis and effective anti-viral responses capable of attacking the virus reservoir," the authors conclude. "Thus, Tat immunization represents a promising pathogenesis-driven intervention to intensify HAART efficacy."