Immunization with Single-Cycle SIV Significantly Reduces Viral Loads After an Intravenous Challenge with SIVmac239
Figure 9
Both immunization regimens afford significant containment of SIVmac239 replication after challenge.
Each of the scSIV-immunized animals in Groups A and B and four unimmunized control animals (Group C) were challenged intravenously with 10 animal infectious doses (1.5 pg p27) of SIVmac239. Viral loads for individual animals (A) and the geometric means for each group (B) are shown. Viral RNA loads were determined using a quantitative reverse-transcription-PCR assay with a threshold of detection of 15 copy eq./ml (dotted line). Mm 416-02 did not become infected and was not included in the calculation of the geometric mean for Group A. At the time that this manuscript was prepared, 7 of the 16 animals in this study had been euthanized with symptoms of AIDS. These animals included Mm 370-03 (week 27), Mm 465-02 (week 30), Mm 350-03 (week 49), Mm 349-03 (week 51), Mm 377-03 (week 60), Mm 295-00 (week 65), and Mm 364-03 (week 68). The clinical conditions of these animals at the time of euthanasia are described in the Materials and Methods section.