FIG. 5.

Characterization of SHIV-SF162P4 neutralization sensitivity. Neutralizing titers (ID₅₀) against the pseudoviruses SF162 and SHIV-SF162P4 clone 41.1 and the replication-competent SHIV-SF162P4 stock in plasma samples from immunized animals (wt, 368, and 423/425/431; n = 5 per group) was determined 2 weeks after immunization 5. Plasma was preincubated with YU2 V3 peptide or scrambled control peptide before being added to the neutralization assay mixture. Neutralization due to V3-directed Abs was calculated as fold reduction of ID₅₀ in comparison to that for mock infection. Significance was evaluated with the Mann-Whitney U test.