LOCAL PERIOCULAR VACCINATION PROTECTS AGAINST EYE DISEASE MORE EFFECTIVELY THAN SYSTEMIC VACCINATION FOLLOWING PRIMARY OCULAR HERPES-SIMPLEX VIRUS-INFECTION IN RABBITS

Vaccination of experimental animals can provide efficient protection a gainst ocular herpes simplex virus type 1 (HSV-I) challenge. Although it is suspected that local immune responses are important in protectio n against ocular HSV-1 infection, no definitive studies have been done to determine if local ocular vaccination would produce more efficacio us protection against HSV-1 ocular challenge than systemic vaccination . To address this question, we vaccinated groups of rabbits either sys temically or periocularly with recombinant HSV-2 glycoproteins B (gB2) and D (gD2) in MF59 emulsion or with live KOS (a nonneurovirulent str ain of HSV-1). Three weeks after the final vaccination, all eyes were challenged with McKrae (a virulent, eye disease-producing strain of HS V-1). Systemic vaccination with either HSV-I KOS or gB2/gD2 in MF59 di d not provide significant protection against any of the four eye disea se parameters measured (conjunctivitis, iritis, epithelial keratitis, and corneal clouding). In contrast, periocular vaccination with gB2/gD 2 in MF59 provided significant protection against conjunctivitis and i ritis, while ocular vaccination with live HSV-1 KOS provided significa nt protection against all four parameters. Thus, local ocular vaccinat ion provided better protection than systemic vaccination against eye d isease following ocular HSV-1 infection. Since local vaccination shoul d produce a stronger local immune response than systemic vaccination, these results suggest that the local ocular immune response is very im portant in protecting against eye disease due to primary HSV-I infecti on. Thus, for clinical protection against primary HSV-1-induced cornea l disease, a local ocular vaccine may prove more effective than system ic vaccination.