title: Effect of the purification process and the storage conditions on the efficacy of an inactivated vaccine against heartwater.
abstract: This work evaluates the effect of purification process and storage conditions (buffer formulation and temperature) on the efficacy of Ehrlichia ruminantium (ER) elementary bodies to be used as an inactivated vaccine candidate against heartwater. In vitro assays revealed that, to avoid major losses in ER integrity and corresponding antigenic properties, a buffer with pH between 5.6 and 8 and an osmolality above 100 mOsmol/kg H(2)O is recommended. Amongst the tested formulations, both PBS and NaCl have shown to stabilize ER antigens at -20 degrees C. To assess the protective properties of the different vaccine formulations, in vivo experiments were performed using a goat model. The results obtained showed that the preparation of ER antigens using a novel membrane-based purification strategy and a simple vaccine formulation (NaCl, -20 degrees C) induced equivalent protection to the conventional vaccine based on ER antigens prepared by a multistep centrifugation methodology and stored at -20 degrees C in PBS buffer.
authors.affiliation: IBET/ITQB, Apartado 12, 2780-901 Oeiras, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Marcelino
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vachiéry
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Amaral
authors.forename: António
authors.initials: A
authors.lastname: Roldão
authors.forename: Thierry
authors.initials: T
authors.lastname: Lefrançois
authors.forename: Manuel J T
authors.initials: MJ
authors.lastname: Carrondo
authors.forename: Paula M
authors.initials: PM
authors.lastname: Alves
authors.forename: Dominique
authors.initials: D
authors.lastname: Martinez
mesh_terms: D000465:Algorithms; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000737:chemistry* / Q000302:isolation & purification / Q000627:therapeutic use*; D002417:Cattle; D002626:Chemistry, Pharmaceutical; D006224:Cricetinae; D004536:Ehrlichia / Q000254:growth & development / Q000276:immunology*; D042783:Endothelial Cells / Q000276:immunology; D006041:Goats / Q000276:immunology; D006357:Heartwater Disease / Q000276:immunology* / Q000517:prevention & control*; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D009994:Osmolar Concentration; D013696:Temperature; D014462:Ultrafiltration; D015164:Vaccines, Inactivated / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D015164:Vaccines, Inactivated