FIG. 4.

Neutralizing activities of rhesus macaque sera. Neutralization activities against the SF162 and SF162ΔV2 viruses of sera collected from animals immunized with the modified ΔV2 gp140 (A) and the unmodified (B) SF162 gp140 immunogens were determined as described in Materials and Methods. Dashed lines indicate 50, 70, and 90% inhibition of infection. Results are representative of three to five independent experiments. Data indicate the mean and standard deviation from triplicate wells. Pre-bleeds, sera collected before vaccination; 2nd DNA and 3rd DNA, sera collected 1 month following the second and the third, respectively, DNA administrations; 2 and 4 weeks post 1st boost, sera collected 2 and 4 weeks, respectively, following the DNA-plus-protein booster immunization.