FIG. 6.

Comparison of breadth and potency of the antibody response induced by selected V region mutants. (A) IC₅₀ titers against four clade B primary isolates are indicated (see Materials and Methods). Results are the means ± standard errors of four guinea pig sera for each construct. The statistically significant differences between ΔV₁V₂V₃(1AB) and the wild-type gp140/145 are shown (Mann-Whitney test). (B) Four individual sera from ΔV₁V₂V₃(1AB)-immunized guinea pigs were screened against a panel of 10 primary viruses. Sera were tested at a 1:5 dilution. Percentages of neutralization (compared with corresponding preimmune sera) are indicated. Data shown are averages of two experiments.