Evaluation of Participants and Follow-up

Study participants were clinically evaluated, and laboratory safety monitoring (hematology, serum chemistries, and liver enzymes) was performed at baseline and at weeks 1, 4, 6, 8, 12, 14, 16, 24, and 36. Safety of each vaccine dosing was assessed 2 to 3 days later by telephone contact. Participants used vaccine report cards after each vaccination to record daily temperatures, injection site reactions, and adverse systemic signs and symptoms. Plasma HIV-1 RNA levels were measured at a single ACTG laboratory (Johns Hopkins University) using the Amplicor HIV-1 Monitor test (version 1.5; Roche Diagnostics, Indianapolis, IN) at baseline and at weeks 4, 12, 16, and 36. CD4⁺ and CD8⁺ T-cell counts were assayed at baseline and weeks 8, 16, and 36. Plasma and peripheral blood mononuclear cells were drawn for frozen storage to perform subsequent immunologic assays within 14 days before study entry (preentry), at study entry, and at weeks 4, 8, 12, 14, 16, and 36. Serum samples were obtained for anti-IL-12 antibodies at entry and at weeks 16 and 36.

Participants completed a tolerability questionnaire at weeks 0, 4, and 12 after vaccination administration, rating the pain they experienced at various steps of vaccine administration if an EP device was used to administer the vaccine. All participants were asked whether the study vaccination procedure they experienced would be acceptable to them as a part of a treatment for HIV infection or would be acceptable if their participation contributed to increased scientific knowledge about vaccine administration to prevent or treat infection.

Information on the perceived pain associated with use of the EP device was collected by asking participants to write down a number and make a vertical mark on a line that represented the pain scale from 0 (no pain) to 10 (worst possible pain), respectively for each time point.