FIG. 2.

Neutralizing antibody response in peptide-immunized animals before and after challenge with SHIV-89.6. Animals were inoculated with either C4/scbl-V3 (A) or C4/89.6-V3 (B) at weeks 0, 4, 12, 24, 89, 95, 101, and 111 and were challenged with SHIV-89.6 at week 113. Neutralizing antibodies to SHIV-89.6 were measured in MT-2 cells at multiple times before and after challenge. Peptide inoculations were made at the times indicated (∧). Arrow, day of challenge. The lowest serum dilution tested was 1:20 (negative results were given a value of 20 for presentation).