FIG. 3.

Serum antibody responses to monomeric HIV-1₆₁₀₁ Env gp120 in rhesus macaques after pDNA immunization. Two weeks after the final pDNA immunization, geometric mean HIV-1₆₁₀₁ Env gp120-specific IgG antibody titers (± standard errors) were determined by ELISA. Antibody end-point titers are reported as the highest reciprocal dilutions of sera giving OD₄₅₀ readings threefold higher than those for week 0 (preimmune) samples. HIV-1₆₁₀₁ gp120-specific antibody titers for group 4a were below the limit of detection (i.e., <1:100).