FIG. 1.

HIV-1-specific antibody responses induced by DNA vaccination via the i.m. (A) and i.n. (B) routes. BALB/c mice were immunized with 5 μg of IIIB/REV formulated with the indicated doses of QS-21. Inoculation was performed twice with a 2-week interval. The HIV-1 env-specific antibody titers were determined by EIA in duplicate on samples collected 2 weeks following the second immunization. The results are expressed as means ± SEM for six (experimental group) or four (control group) mice. ∗, significant enhancement of the antibody response compared with IIIB/REV alone (P < 0.05). Similar results were obtained in a repeat experiment (not shown). N.D., not detected.