Intranasal vaccination of dogs with liver avirulent Bordetella bronchiseptica: correlation of serum agglutination titer and the formation of secretory IgA with protection against experimentally induced infectious tracheobronchitis.

Dogs inoculated intranasally with a live avirulent Bordetella bronchiseptica vaccine were monitored for the development of resistance to experimentally induced infectious tracheobronchitis (canine cough). Dogs were challenge exposed with a virulent strains of B bronchiseptica at various times after they were vaccinated. Clinical protection was detectable as early as 48 hours. At postvaccination days 4, 5, and 14, 56%, 83%, and 95% protection was observed. Humoral immunoglobulin (Ig) titers ranged from 1:8.6 on day 0 to 1:147 on postvaccination day 21. In the monitoring of B bronchiseptica-specific secretory IgA by indirect immunofluorescence, titers appeared as early as day 4 after vaccination. The IgA titers ranged from 1:16 on day 4 to 1: 1,024 on day 21. The appearance of IgA titers correlated with the development of resistance to clinical infection.

Efficacy of Bordetella bronchiseptica bacterin in controlling enzootic atrophic rhinitis in swine.

The efficacy of a Bordetella bronchiseptica bacterin was evaluated in 2 commercial swine herds affected with mild and severe enzootic atrophic rhinitis (AR). In the 1st herd study, (mild AR), the degree of clinical AR, nasal turbinate evaluation, blood serum titer to B bronchiseptica antigen, and adjusted days from birth to 100 kg were determined for individual pigs. Bacterin inoculation reduced the incidence and severity of gross turbinate atrophy 57% and reduced clinical AR over 93%. Inoculated swine had an average blood serum-agglutinating titer greater than 1:2,793 and noninoculated (control) swine had an average titer of 1:112. Increased serum titer significantly (P less than 0.05) correlated with decreased degree of nasal turbinate atrophy. Inoculated and control pigs reached 100 kg in an average of 171 and 178 days after birth, respectively. In the 2nd study (severe enzootic AR), inoculated and control pigs were individually evaluated for clinical AR and total average daily weight gain. Inoculation reduced clinical AR over 90%. The total average daily gain for the inoculated and control pits was 435.84 g and 340.50 g, respectively. Inoculated pigs and control pigs reached 100-kg market weight in 184 and 238 days, respectively.

Mouse potency assay for Bordetella bronchiseptica bacterins.

A potency assay for Bordetella bronchiseptica bacterins has been developed using mice. The immunogenicities of three bacterins, B, C, and D, were evaluated for ability to prevent death in mice as compared with a reference standard bacterin (RSB-A). Bacterins RSB-A, B, and C were evaluated for ability to prevent death in mice as compared with a reference standard bacterin (RSB-A). Bacterins RSB-A, B, and C were evaluated in swine for efficacy against nasal turbinate atrophy. Swine immunized with RSB-A demonstrated 25% gross nasal turbinate atrophy (GNTA), whereas nonimmunized swine had 85% GNTA. Swine vaccinated with bacterins B and C demonstrated 0 and 100% GNTA, respectively, whereas the nonimmunized groups had 64 and 75% GNTA, respectively. RSB-A and bacterins B, C, and D provided average mouse survivals of 94, 88, 49, and 32%, respectively when the mice were given 1/10,000 of a recommended swine-immunizing dose, whereas an average of 88% of the unvaccinated mice died.