Rhesus macaques were immunized with single-cycle SIV by two different regimens.

<p>(A) Six animals in Group A were inoculated with 6 identical doses of scSIV at 8-week intervals. Each dose consisted of a mixture of scSIV_mac239 TM_open, scSIV_mac316 TM_open, and scSIV_mac155T3 TM_open (5 µg p27 eq. each). (B) Six animals in Group B were primed with a mixture of scSIV_mac239 TM_stop, scSIV_mac316 TM_stop, and scSIV_mac155T3 TM_stop (5 µg p27 eq. each) and boosted on weeks 12 and 24 with VSV G trans-complemented scSIV (10 and 13 µg p27 eq., respectively). Single-cycle SIV_mac239 TM_open was trans-complemented with the Indiana serotype of VSV G for the first boost (week 12) and the New Jersey serotype of VSV G for the second boost (week 24). (A,B) Twelve weeks after the last dose of scSIV, Groups A and B and four unvaccinated control animals were challenged intravenously (i.v.) with SIV_mac239.