VACCINATION OF CATTLE AGAINST EXPERIMENTALLY INDUCED THROMBOEMBOLIC MENINGOENCEPHALITIS WITH A HEMOPHILUS-SOMNUS BACTERIN

  • 1 January 1982
    • journal article
    • research article
    • Vol. 43  (8) , 1339-1342
Abstract
The capability of a commercial H. somnus bacterin to protect cattle against experimentally induced thromboembolic meningoencephalitis was examined. Eighteen cattle were vaccinated twice, 8 were vaccinated once and 14 were nonvaccinated controls. Serum antibody responses to vaccination were measured by gel immunodiffusion, bacterial agglutination test and complement-fixation test. Deaths occurred in 8 of the 14 controls, 3 of the cattle vaccinated once and 3 of the cattle vaccinated twice. Two vaccinations gave significant protection against challenge exposure (P < 0.05). There were no cattle which gave positive reactions in the gel immunodiffusion test and significant changes in the bacterial agglutination test titers were not seen in the cattle after vaccination. There was a significant (P L 0.01) increase in the complement-fixation test titers of cattle vaccinated twice. Serum antibody titers were unrelated to the outcome of challenge infection, regardless of vaccination status, in any of the serotests.