PURPOSE. The goal of this study was to use multiple quantitative disease measures to evaluate the effect of various viral inocula on the development of vaccinia keratitis in rabbits. METHODS. Trephined eyes of female rabbits were infected with 104, 105, 106, or 107 plaque-forming units (pfu) of the Dryvax strain of the vaccinia virus and scored daily for disease for 14 days according to a modification of the MacDonald-Shadduck scoring system. Ocular viral titers and vaccinia-specific antibody titers were determined by plaque assay and ELISA, respectively. RESULTS. The amount of virus used for infection affected the severity of disease, with 104 pfu eliciting milder keratitis afterdelayed onset compared with higher amounts of virus. At inocula above 105 pfu the course and severity of corneal disease was not significantly different. The time to reach peak titers was delayed in the 104 group but peak titers were similar in all groups. Severe conjunctival chemosis interfered with scoring in animals infected with 106 or 107 pfu. Virus-specificantibody titers were similar in all groups at day 14. Body weights decreased less than 10% in all groups. CONCLUSIONS. The course of vaccinia keratitis in rabbits paralleled that in humans. A viral inoculum of 105 pfu/eye was determined to be optimal for use in further studies of vaccinia keratitis.
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience