title: Efficacy, safety, and immunogenicity of a meningococcal group B (15:P1.3) outer membrane protein vaccine in Iquique, Chile. Chilean National Committee for Meningococcal Disease.
abstract: A meningococcal group B (15:P1.3) outer membrane protein vaccine was tested for efficacy in a randomized, double-blind controlled study in Iquique, Chile. A total of 40 811 volunteers, ages 1-21 years, enrolled in the study. Volunteers received two doses of vaccine six weeks apart by jet injector. Both the experimental vaccine and the control vaccine (Menomune, A, C, Y and W135 meningococcal polysaccharide vaccine) were well tolerated with minor side-effects. Active surveillance for suspected cases of meningococcal disease was conducted for 20 months in Iquique. Eighteen cases of group B meningococcal disease were confirmed during the 20 months. Efficacy was estimated to be 51% (p = 0.11) for all ages combined. In children aged 1-4 no protection was evident, but in volunteers aged 5-21 vaccine efficacy was 70% (p = 0.045). The IgG antibody response by ELISA was characterized by a large booster effect after the second dose, followed by a substantial drop in antibody levels by 6 months. The youngest children had the highest responses. The bactericidal antibody response, on the other hand, was characterized by the lack of a significant booster response, higher responses in the older children, and an increase in the geometric mean titer in the later months of the study in the older children.
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D002677:Chile; D003165:Complement System Proteins / Q000378:metabolism; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008581:Meningitis / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control; D009345:Neisseria meningitidis / Q000276:immunology*; D010614:Pharynx / Q000382:microbiology; D018272:Porins; D011446:Prospective Studies
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D018272:Porins; C057699:porin protein, Neisseria; D003165:Complement System Proteins