Immunisation of cattle and buffaloes with live haemorrhagic septicaemia vaccine

Safety and protective efficacy of intramuscular vaccination with a live aroA derivative of Pasteurella multocida B:2 against experimental hemorrhagic septicemia in calves

Three groups of five calves, namely, V1, V2, and V3, were immunized intramuscularly at 4 and 8 weeks of age with ca. 10(9), 10(8), and 10(7) CFU, respectively, of a derivative of Pasteurella multocida B:2 wild-type strain 85020 containing a deletion in the aroA gene (strain JRMT12). The first and second vaccinations resulted in significantly (P < 0.01) higher rectal temperature responses in groups V1 and V2 than in group V3. Serum immunoglobulin M (IgM) and IgG titers did not increase in any group until after the second vaccination and were then significantly higher in groups V1 and V2 than in group V3 (P = 0.001 for both IgM and IgG). All vaccinated groups and three unvaccinated challenge control calves (group CC) were injected subcutaneously at 10 weeks of age with ca. 10(7) CFU of strain 85020. Vaccinated calves survived the challenge, but two CC animals developed clinical disease and were killed for humane reasons. After challenge, mean serum amyloid A concentrations were significantly higher (P < 0.001) in the CC group than in the vaccinated groups. Postmortem examination revealed that calves in the CC group showed the most extensive range of bacteriologically positive tissues and gross and histopathological lesions. Overall, a clear dose-dependent response was present, with those receiving a higher vaccine dose being less affected clinically, bacteriologically, and pathologically by the wild-type challenge. The V2 treatment appeared to give the best combination of high immune response, protection, and safety.

Safety, efficacy and cross-protectivity of a live intranasal aerosol haemorrhagic septicaemia vaccine

The safety, efficacy and cross-protectivity of a live intranasal aerosol haemorrhagic septicaemia vaccine containing Pasteurella multocida serotype B:3,4 were tested in young cattle and buffaloes in Myanmar, where more than 1.5 million animals had been inoculated with this vaccine between 1989 and 1999. A recommended dose of 2 x 10(7) viable organisms was used for the efficacy test. The administration of 100 times the recommended dose to 50 cattle and 39 buffalo calves was innocuous. Seven months after they were vaccinated, three of three buffaloes were protected and 12 months after they were vaccinated, three of four buffaloes were protected against a subcutaneous challenge with serotype B:2 which killed three of three unvaccinated buffaloes. Twelve months after they were vaccinated, eight of eight cattle survived a serotype B:2 challenge, which killed four of four unvaccinated controls. The vaccinated cattle had developed serum antibodies detectable by the passive mouse protection test. Indirect haemagglutination tests on sera taken from cattle 10 days and five weeks after they were vaccinated showed high titres of antibodies. The serum of vaccinated cattle cross-protected passively immunised mice against infection with P. multocida serotypes E:2, F:3,4 and A:3,4.

Haemorrhagic septicaemia vaccines

Haemorrhagic septicaemia (HS), an economically important disease of cattle and buffaloes, is caused by Pasteurella multocida (6:B). Vaccination against this disease is widely practised. Plain broth bacterins, or alum precipitated and aluminium hydroxide gel vaccines are administered twice a year since these vaccines offer an immunity of 4-6 months. Many countries use oil adjuvant vaccine (OAV), which gives both a higher degree and a longer duration of immunity up to 1 year. A double emulsion and multiple emulsion vaccine consisting of a thin viscosity have also been experimentally developed that gave an immunity parallel to OAV. Recently, a live vaccine developed from a fallow deer strain (B:3,4) has been used in Myanmar that offers an immunity for more than a year but is not free from constraints. The present review provides information on HS vaccines developed from time to time using whole bacteria or their components. The kinetics and isotype of antibody and cell-mediated immune responses have also been poorly understood so far, and hence information on their role in protection against HS is reviewed.