FIG 8.

Inhibition of the SIVsm Env panel by pools of serum from vaccinated monkeys organized by infection status after 12 challenges. Pools of serum from immunized rhesus macaques that became infected after 12 challenges with SIVsmE660 (breakthrough) or did not become infected (protected) were created for each trial. Details about the animals from which serum was collected are provided in Table S1 in the supplemental material. Serum pools were serially diluted 5-fold and used to inhibit pseudovirus infection using the Tzm-bl cell assay, with luciferase activity being the readout. The reciprocal dilution is presented on the x axis on a log₁₀ scale, and the percent viral infectivity relative to that in the absence of test plasma/serum (100%) is shown on the y axis. The Env pseudoviruses were grouped according to tier, which is indicated in the legend. Closed symbols and solid lines, vaccinated animals that experienced breakthrough infections; open symbols and dashed lines, vaccinated animals that were protected after 12 challenges. Each Env pseudovirus and serum combination was tested in duplicate wells in at least two independent experiments. The standard error of the mean is shown for each point on the graph.