title: Persisting immune responses indicating long-term protection after booster dose with meningococcal group B outer membrane vesicle vaccine.
abstract: MenBvac is an outer membrane vesicle vaccine against systemic meningococcal disease caused by serogroup B Neisseria meningitidis. In this placebo-controlled double-blind study including 374 healthy adolescents, the safety and immunogenicity of a schedule of three primary doses 6 weeks apart followed by a fourth dose a year later were evaluated. Antibody responses to the vaccine strain and heterologous strains (non-vaccine-type strains) and the persistence of these antibodies were measured by the serum bactericidal assay (SBA) and enzyme-linked immunosorbent assay up to 1 year after the last dose. The proportion of subjects with SBA titers of > or = 4 against the vaccine strain increased from 3% prevaccination to 65% after the third dose. Ten months later, this proportion had declined to 28%. The fourth dose induced a booster response demonstrated by 93% of subjects achieving a titer of > or = 4. One year after the booster dose, 64% still showed SBA titers of > or = 4. Cross-reacting antibodies were induced against all heterologous strains tested, although the magnitude of SBA titers differed widely between the different strains. All four doses of MenBvac were safe. Both MenBvac and the placebo had reactogenicity profiles of mild to moderate local and systemic reactions. Pain, the most common reaction, was reported with similar frequencies in both groups. No serious adverse events occurred in the MenBvac group. This study confirmed the good immunogenicity of the primary course of MenBvac and demonstrated prolonged persistence and increased cross-reactivity of functional antibodies elicited by a booster dose.
authors.affiliation: Division of Infectious Disease Control, Norwegian Institute of Public Health (NIPH), P.O. Box 4404, Nydalen, N-0403 Oslo, Norway. Berit.Feiring@fhi.no
authors.forename: Berit
authors.initials: B
authors.lastname: Feiring
authors.forename: Jan
authors.initials: J
authors.lastname: Fuglesang
authors.forename: Philipp
authors.initials: P
authors.lastname: Oster
authors.forename: Lisbeth M
authors.initials: LM
authors.lastname: Naess
authors.forename: Oddveig S
authors.initials: OS
authors.lastname: Helland
authors.forename: Sandrine
authors.initials: S
authors.lastname: Tilman
authors.forename: Einar
authors.initials: E
authors.lastname: Rosenqvist
authors.forename: Marianne A R
authors.initials: MA
authors.lastname: Bergsaker
authors.forename: Hanne
authors.initials: H
authors.lastname: Nøkleby
authors.forename: Ingeborg S
authors.initials: IS
authors.lastname: Aaberge
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D001425:Bacterial Outer Membrane Proteins / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D001770:Blood Bactericidal Activity; D003429:Cross Reactions; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D008297:Male; D008589:Meningococcal Infections / Q000517:prevention & control; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D038541:Neisseria meningitidis, Serogroup B / Q000145:classification / Q000276:immunology*; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D022401:Meningococcal Vaccines