title: Comparative efficacy of ten commercial Campylobacter fetus vaccines in the pregnant guinea pig: challenge with Campylobacter fetus serotype A.
abstract: Efficacy of ten commercial Campylobacter fetus vaccines was tested in pregnant guinea pigs and compared with that of an experimental vaccine prepared from the challenge-exposure strain. If the first lot of vaccine failed to protect 50% of the guinea pigs, one or two additional lots of that vaccine were purchased and retested. Three vaccines for cattle, evaluated, as the most effective of those tested, protected 62%, 72%, and 89% of the guinea pigs from abortion; the experimental vaccine protected 98%. The two vaccines for sheep protected 50% and 61% of the guinea pigs from abortion. With the other five vaccines produced for immunizing cattle, protection was from 0% to 36%, with the exception of one lot of a vaccine that protected 74%. Blood infection was found at necropsy in only 6% of the guinea pigs given vaccines that protected 50% or more from abortion, but was found in 66% of those given vaccines that protected less than 50%. Similarly, tissue infection was found at necropsy in only 18% of the guinea pigs given vaccines that protected more than 50%, but was found in 91% of those given vaccines that protected less than 50% from abortion. Oil-emulsion adjuvants appeared to enhance protection from abortion and infection. Nodules persisted at the injection site in most of the guinea pigs immunized with vaccines containing oil-emulsion adjuvants, but rarely persisted in guinea pigs given aqueous-phase adjuvant vaccines. Comparison of efficacy of the vaccines in guinea pigs with efficacy in sheep and cattle remains to be made.
mesh_terms: D000034:Abortion, Veterinary / Q000517:prevention & control*; D000818:Animals; D001428:Bacterial Vaccines; D002167:Campylobacter / Q000276:immunology*; D002169:Campylobacter Infections / Q000517:prevention & control / Q000662:veterinary*; D002168:Campylobacter fetus / Q000276:immunology*; D002417:Cattle; D005260:Female; D006168:Guinea Pigs; D011247:Pregnancy; D012376:Rodent Diseases / Q000517:prevention & control*; D012756:Sheep
chemical_list: D001428:Bacterial Vaccines