DNA/rAd5 Vaccine Regimen Lacks Efficacy for HIV-1
(HealthDay News) – For individuals at high risk of HIV-1 infection, a DNA prime-recombinant adenovirus type 5 boost (DNA/rAd5) vaccine regimen lacks efficacy, according to a study published online Oct. 7 in the New England Journal of Medicine to coincide with presentation at the AIDS Vaccine 2013 meeting, held from Oct. 7–10 in Barcelona, Spain.
Scott M. Hammer, MD, from Columbia University in New York City, and colleagues randomized 2,504 men or transgender women who have sex with men to receive DNA/rAd5 vaccine (1,253 participants) or placebo (1,251 participants). The authors sought to examine the efficacy of the vaccine regimen among those at increased risk of HIV-1 infection.
Vaccinations were halted in April 2013 for lack of efficacy. In the primary analysis, the researchers found that Week 28+ infection (HIV-1 acquisition from Week 28 through Month 24) was diagnosed in 27 and 21 participants in the vaccine and placebo groups, respectively (P=0.44). The mean viral-load set points were 4.46 and 4.47 HIV-1 RNA log10 copes/mL in the vaccine and placebo groups, respectively. A lack of vaccine efficacy was also noted in analyses of all infections (41 in the vaccine group and 31 in the placebo group; P=0.28). The vaccine regimen side effect profile was acceptable.
"Our study gave a definitive, albeit disappointing, result but should provide useful information as newer vaccine regimens and approaches are developed," the authors write.