A crude cytotoxin vaccine protects sheep against experimental Pasteurella haemolytica serotype A2 infection.
Three vaccines containing Pasteurella haemolytica serotype A2 antigens were tested for their ability to protect sheep against a homologous challenge. A crude cytotoxin preparation in combination with a sodium salicylate extract (SSE) or crude cytotoxin alone were highly protective (98 and 86%, respectively), whereas SSE alone was poorly (47%) protective. These findings indicated that the crude cytotoxin was an essential component of a protective vaccine. Protection correlated with serum cytotoxin-neutralising (CN) titres and bactericidal activity, which were stimulated by antigens in the crude cytotoxin preparation.
Sutherland
A D
AD
Moredun Research Institute, Edinburgh, Gt. Britain.
Donachie
W
W
Jones
G E
GE
Quirie
M
M
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines; D003603:Cytotoxins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D009500:Neutralization Tests; D010325:Pasteurella / Q000276:immunology*; D010326:Pasteurella Infections / Q000517:prevention & control / Q000662:veterinary*; D011897:Random Allocation; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*; D013047:Specific Pathogen-Free Organisms; D014611:Vaccination / Q000662:veterinary
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D003603:Cytotoxins