OBJECTIVE: The objective of this study was to determine the ability of a modified live intranasal Bordetella bronchiseptica vaccine (Nobivac-Bb) to prevent disease in cats for a period of one year following vaccination.

EXPERIMENTAL DESIGN: Forty-eight cats were vaccinated according to manufacturer's instructions. Twenty-four vaccinated cats and 12 controls were challenged with a virulent strain of B. bronchiseptica six-months after vaccination, and two additional groups of vaccinates and controls were challenged one year after vaccination. Clinical signs were recorded daily for two weeks after challenge, and clinical scores were calculated for each group. The Mann-Whitney U test was used to determine if clinical scores in the vaccinated groups were significantly different from scores in the control groups.

RESULTS: The mean clinical score for vaccinated cats at six-months after vaccination was 1.3, compared to 13.3 for control cats, corresponding to a 90% reduction in clinical scores. At one-year post-vaccination, mean clinical score for vaccinated cats was 0.9, compared to 9.9 for control cats, again corresponding to a 90% reduction in clinical scores.

CONCLUSION: The results from this study demonstrate that Nobivac-Bb was able to protect cats from disease for a period of at least one year after a single intranasal vaccination.