FIG 5.

Kaplan-Meier rate of infection after repeated intrarectal challenges with SIVmac239. Macaques in groups 1 and 2 were inoculated with 200 TCID₅₀ of SIVmac239 via the i.r. route on a weekly basis. The infecting exposure for each animal is shown in Table 1. The rate at which vaccinees in group 1 acquired SIV infection was not significantly different from that exhibited by their group 2 counterparts (P = 0.992, according to the log rank test).