Effects of a single dose of an intranasal feline herpesvirus 1, calicivirus, and panleukopenia vaccine on clinical signs and virus shedding after challenge with virulent feline herpesvirus 1

Abstract

The objective of this study was to determine whether intranasal administration of a commercially available FVRCP vaccine to kittens lessened clinical signs and feline herpesvirus 1 (FHV-1) viral shedding when compared to unvaccinated control kittens after FHV-1 challenge. Three groups of 10 unvaccinated kittens were administered one dose of vaccine 6 days (group 1), 4 days (group 2), or 2 days (group 3) before challenge, respectively. One group was maintained as unvaccinated controls (group 4). FHV-1 challenge was then induced and the kittens were observed for 14 days. When the grouped vaccinated kitten results (groups 1-3) were compared to group 4 results, clinical scores following challenge were significantly lower (P<0.05) and significantly lower body temperatures (P<0.05) were detected on days 0, 5 and 9 post-challenge. When evaluated by individual group, group 1 and group 2 kittens had significantly lower clinical scores (P<0.05) than group 4 kittens post-challenge. In addition, FHV-1 shedding was lower in group 1 kittens when compared to group 4 kittens on day 6 after challenge (P<0.05). Administration of this vaccine within several days prior to exposure lessened clinical signs of disease and FHV-1 shedding compared to unvaccinated kittens.

Fig 1

Mean ranks of clinical scores between groups of kittens vaccinated 6 days (group 1), 4 days (group 2), or 2 days (group 3) before challenge and control kittens (group 4). Data are from the cumulative score by group collected days 0–14 after challenge with FHV-1. *=statistically different than group 4.

Fig 2

Mean ranks of combined clinical scores between groups of vaccinated kittens (groups 1–3) and control kittens (group 4). Data are from the cumulative score by group collected days 0–14 after challenge with FHV-1. *=statistically different from group 4 at P<0.05 by Wilcoxon's rank sum test.