FIGURE 5

ICR immunization provides comparably effective mucosal protection against HSV-2 transmitted through either rectal or vaginal mucosa. Mice were immunized by ICR (2 10⁹ PFU), IN (5 10⁸ FPU), SC (5 10⁸ PFU), or unimmunized before HSV-2 challenge. Pathology score (left panels), virus replication (middle panels), and mortality (right panels) were examined after either rectal or vaginal challenge. (a) Mice were challenged rectally with 2 10⁶ PFU of HSV-2 3 weeks after immunization by ICR (N=10), IN (N=8), SC (N=7), or without immunization (N=13). No differences in pathology score or viral shedding were found between IN and SC, but both groups were statistically different from the unimmunized group (left panel, P<0.05 and middle panel). IN differed from unimmunized in mortality (right panel, P<0.01). (b) Mice were challenged vaginally with 2 10⁵ PFU of HSV-2 3 weeks after immunization by ICR (N=9), IN (N=7), SC (N=7), or without immunization (N=10). A significant difference in mortality was also found between IN and SC in vaccinated animals (right panel, P<0.05), but not in viral shedding or pathology score. IN, but not SC, was statistically different from unimmunized in both pathology score (left panel, P<0.01) and mortality (right panel, P<0.05). Asterisks of pathology score and mortality indicate a statistical difference of the group in comparison with the ICR immunization group. *, **, and *** indicate P<0.05, 0.01, and 0.001, respectively. ICR, intracolorectal; HSV-2, herpes simplex virus type 2; PFU, plaque-forming unit; IN, intranasal; SC, subcutaneous.