Objectives: To assess whether therapeutic vaccination with ALVAC-HIV ± Remune affects viral reservoir size in antiretroviral therapy-treated individuals.
Methods: Participants in CTN 173, a multicentre, randomized, 3-arm, placebo-controlled, double-blind study, were vaccinated with ALVAC-HIV ± Remune (groups 1 and 2, respectively) or with placebos (group 3) over 20 weeks and assessed for changes in the size of their viral reservoirs from weeks 0 to 24.
Results: Sixteen participants completed the viral reservoir substudy. The median sizes (interquartile range) of the viral reservoir at baseline (week 0) were 0.07 (0.03-0.37), 0.04 (0.02-0.33), and 0.13 (0.06-0.99) infectious units per million peripheral blood mononuclear cells for groups 1, 2, and 3, respectively; these baseline viral reservoir sizes were not significantly different (P = 0.37). By week 24, the median sizes of the viral reservoirs were 0.04 (0.01-2.16), 0.04 (0.01-0.34), and 0.12 (0.01-0.44) infectious units per million peripheral blood mononuclear cells for groups 1, 2, and 3 respectively; these week 24 viral reservoir sizes were not significantly different (P = 0.91). Furthermore, there were no statistically significant differences between baseline and week 24 reservoir sizes for any of the 3 groups (P = 0.88, P = 1.00, and P = 0.44, respectively).
Conclusions: Despite evidence that ALVAC-HIV ± Remune was associated with a trend toward a delay in viral rebound and a smaller decrease in CD4 T-cell counts following antiretroviral therapy interruption, ALVAC-HIV ± Remune did not influence the size of the viral reservoir.