Serologic responses of young colostrum fed dairy calves to antigens of Pasteurella haemolytica A1

• Published in: Vaccine Vol. 16; no. 20; pp. 2018 - 2025
• Main Authors: Hodgins, Douglas C., Shewen, Patricia E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-12-1998; Elsevier
• Subjects: active immune response; Animals; Antibodies, Bacterial - biosynthesis; Antigens, Bacterial - immunology; Antigens, Surface - immunology; Bacterial Toxins - immunology; Bacterial Vaccines - immunology; Bacteriology; Biological and medical sciences; capsular polysaccharide; Cattle; Cytotoxins - immunology; Exotoxins - immunology; Fundamental and applied biological sciences. Psychology; Immunoenzyme Techniques; Immunoglobulin M - biosynthesis; Immunosuppressive Agents - immunology; leukotoxin; Mannheimia haemolytica - immunology; Maternal antibodies; Microbiology; Neutralization Tests - veterinary; Pasteurella haemolytica; Pasteurella haemolytica A1; Pasteurellosis, Pneumonic - immunology; Pasteurellosis, Pneumonic - prevention & control; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; leukotoxin; capsular polysaccharide; Pasteurella haemolytica A1; Maternal antibodies; active immune response; Immune response; Maternal origin; Bovine; Antibody; Suckling animal; Passive immunity; Vaccine; Pasteurellaceae; Microorganism capsule; Vertebrata; Mammalia; Immunogenicity; Newborn animal; Cross reaction; Bacteria; Artiodactyla; Polysaccharide; Ungulata; Humoral immunity; Pasteurella haemolytica
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(98)00086-3

The potential and limitations of early calfhood vaccination to induce active immunity to
Pasteurella haemolytica A1 in conventional colostrum fed calves were investigated. Holstein dairy calves (
n = 29) were vaccinated at 2 and 4 weeks of age, or at 6 and 8 weeks of age with a commercial culture supernatant vaccine (Presponse
®, Langford Inc., Guelph, Ont., Canada), or remained unvaccinated as controls. Serum antibody titres were measured using an indirect bacterial agglutination assay, a leukotoxin neutralization assay, and enzyme immunoassays for antibodies of the IgM, IgG1, and IgG2 isotypes binding purified capsular polysaccharide of
P. haemolytica A1. Seroconversion (fourfold or greater increase in serum antibody titre) rates were compared using Fisher's exact test. The effects of passive antibody titres and age on response to vaccination were assessed by linear modelling. Vaccination at 2 and 4 weeks of age was associated with 40%, and 0% of calves seroconverting on the basis of agglutinating antibody titres, and leukotoxin neutralizing titres respectively, and 50%, 0%, and 0% seroconverting on the basis of IgM, IgG1 and IgG2 antibodies to capsular polysaccharide, respecitively. Agglutinating antibody responses were not related to prevaccination antibody titres, or to age at vaccination. Higher responses (
p = 0.08) to leukotoxin were observed in older calves (after taking differences in prevaccination titres into account). Statistical analyses of responses to capsular polysaccharide among calves with comparable prevaccination IgG1 antibody titres revealed significantly higher IgM, IgG1 and IgG2 responses in older calves. Rising titres of IgM antibodies in nonvaccinated calves after 5 weeks of age suggest natural exposure to
P. haemolytica A1 or antigens which result in serologic cross-reactions as a means of priming immune responses.