FIG. 2.

ICP10ΔPK immunization prevents HSV-2 replication and disease. (A) Mice (Swiss Webster, 5 weeks old, groups of 10) were given two doses of ICP10ΔPK (3 × 10⁶ PFU) or phosphate-buffered saline (control) by subcutaneous inoculation in the rear right footpad at 10-day intervals and were challenged with HSV-2 (10⁷ PFU) in the contralateral footpad. HSV-2 titers (PFU) in the footpad were determined by plaque assay at various times after challenge. (B) Mice were immunized with ICP10ΔPK or phosphate-buffered saline (control) and were challenged with HSV-2 (5 × 10⁷ PFU) at 10 or 40 days after the last immunization. They were monitored for skin lesions, paralysis, and/or death. Similar protection was observed for animals challenged with HSV-1 instead of HSV-2.