Oral administration of a live-attenuated Bordetella bronchiseptica vaccine (Vanguard B Oral) induces protective immunity against challenge 7 days after vaccination in dogs.

OBJECTIVE

To evaluate the onset of immunity 7 days after administration of a live-attenuated Bordetella bronchiseptica (Bb) vaccine (Vanguard B Oral) in dogs.

METHODS

In a randomized, blinded, controlled study conducted at an animal research facility in 2022, forty 8-week-old Beagle puppies were randomly assigned to 2 groups (n = 20/group) and administered a single oral dose of either placebo or vaccine on day 0. On day 7 after vaccination, all dogs were challenged with aerosolized virulent Bb. Clinical observations were conducted twice on days 0 and 6 through 20 and once daily on days 1 through 5 and 21. Tympanic temperatures were measured twice on day 0 and once daily from days 1 through 21. Microplate agglutination titers were collected from all animals on days -12, 0, 6, and 21.

RESULTS

Coughing on 2 consecutive days occurred in 17 of 20 control dogs (85%) versus 4 of 20 vaccinates (20%). Vaccinated dogs also exhibited fewer coughing observation periods (3.2% vs 15.8%) and a shorter coughing duration of 2.4 days (95% CI, 1.0 to 3.7) than controls (5.5 days; 95% CI, 4.1 to 6.8). Total clinical scores were significantly lower in vaccinated (median, 15.0) dogs than in controls (median, 27.0) and remained significant when ocular and nasal discharge were excluded.

CONCLUSIONS

The vaccine was considered safe, with only sporadic mild clinical signs. After challenge, vaccinated dogs demonstrated a significant reduction in coughing and other clinical signs.

CLINICAL RELEVANCE: Vanguard B Oral elicited a rapid onset of protective immunity against virulent Bb challenge as early as 7 days after vaccination.