title: Optimization of the conjugation method for a serogroup B/C meningococcal vaccine.
abstract: A conjugate meningococcal vaccine against serogroup B/C consisting of capsular PS (polysaccharide) from serogroup C conjugated to OMV (outer membrane vesicle) from serogroup B would be a very useful vaccine in regions where there is a prevalence of both serogroups, for example in Brazil. For this purpose, the conjugation method that uses ADHy (adipic acid dihydrazide) as spacer and a carbodi-imide derivative, EDAC [1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide], as catalyser was optimized looking for synthesis yield and maintenance of the antigenicity of both components. The best synthesis conditions preserving the vaccine immunogenicity resulted in a final yield of approx. 17%. Immunogenicity of the vaccine was highest when 10% of the sialic acid residues of the PS were occupied by the ADHy spacer. Sterilization of the conjugate by filtration through a 0.22-microm-pore-size membrane resulted in a low recovery of protein and PS (approximately 50%), although the vaccine immunogenicity was maintained. Using gamma irradiation on freeze-dried sample, it was possible to maintain the integrity of OMV structure and, consequently, its ability to induce bactericidal antibodies.
authors.affiliation: Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brasil 1500, CEP 05503-900, São Paulo, Brazil.
authors.forename: Lucila O
authors.initials: LO
authors.lastname: Fukasawa
authors.forename: Rocilda P F
authors.initials: RP
authors.lastname: Schenkman
authors.forename: Catia T
authors.initials: CT
authors.lastname: Perciani
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Carneiro
authors.forename: Waldely O
authors.initials: WO
authors.lastname: Dias
authors.forename: Martha M
authors.initials: MM
authors.lastname: Tanizaki
mesh_terms: D000272:Adipates / Q000737:chemistry; D000818:Animals; D016667:Bacterial Capsules; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000737:chemistry; D005260:Female; D005720:Gamma Rays; D022401:Meningococcal Vaccines / Q000276:immunology* / Q000528:radiation effects; D051379:Mice; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D015610:Serum Bactericidal Test; D014462:Ultrafiltration; D018074:Vaccines, Conjugate / Q000737:chemistry* / Q000276:immunology* / Q000528:radiation effects
chemical_list: D000272:Adipates; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate; C039455:capsular polysaccharide, meningococcal group B; C037676:meningococcal group C polysaccharide; D005022:Ethyldimethylaminopropyl Carbodiimide; C010011:adipic dihydrazide