Immunogenicity of 2 Serogroup B Outer-Membrane Protein Meningococcal Vaccines: A Randomized Controlled Trial in Chile.
Tappero, Jordan W. MD, MPH; Lagos, Rosanna MD; Maldonado Ballesteros, Aurora; Plikaytis, Brian MSc; Williams, Derrick BS; Dykes, Janet BA; Gheesling, Linda L. BS; Carlone, George M. PhD; Hoiby, E. Arne MD; Holst, Johan MSc; Nokleby, Hanne MD; Rosenqvist, Einar PhD; Sierra, Gustavo MD; Campa, Concepcion MD; Sotolongo, Franklin PhD; Vega, Jeanette MD; Garcia, Julio MD; Herrera, Patricio MD; Poolman, Jan T. PhD; Perkins, Bradley A. MD
[Article]
JAMA.
281(16):1520-1527, April 28, 1999.
(Format: HTML)
Context: Meningococcal disease occurs worldwide, and serogroup B disease accounts for a large proportion of cases. Although persons younger than 4 years are at greatest risk for serogroup B meningococcal disease, vaccine efficacy has not been demonstrated in this age group.
Objective: To evaluate serum bactericidal activity (SBA) against homologous vaccine type strains and a heterologous Chilean epidemic strain of Neisseria meningitidis as a potential correlate for vaccine efficacy.
Design: Double-blind, randomized controlled trial conducted between March 14 and July 20, 1994. All blood samples were taken by December 1994.
Setting: Santiago, Chile, where a clonal serogroup B meningococcal disease epidemic began in 1993.
Participants: Infants younger than 1 year (n=187), children aged 2 to 4 years (n=183), and adults aged 17 to 30 years (n=173).
Intervention: Participants received 3 doses of outer-membrane protein (OMP) meningococcal vaccine developed in either Cuba or Norway or a control vaccine, with each dose given 2 months apart. Blood samples were obtained at baseline, prior to dose 3, and at 4 to 6 weeks after dose 3.
Main Outcome Measure: Immune response, defined as a 4-fold or greater rise in SBA titer 4 to 6 weeks after dose 3 compared with prevaccination titer.
Results: Children and adult recipients of either meningococcal vaccine were more likely than controls to develop an immune response to the heterologous epidemic strain. After 3 doses of vaccine, 31% to 35% of children responded to the vaccine vs 5% to placebo; 37% to 60% of adults responded to vaccine vs 4% to placebo (P<.05 vs control for all). Infants, however, did not respond. In contrast, against homologous vaccine type strains, the response rate was 67% or higher among children and adults and 90% or higher among infants (P<.001 vs control for all). Subsequent SBA against 7 isogenic homologous target strains identified class 1 OMP as the immunodominant antigen.
Conclusions: These data suggest that neither serogroup B OMP meningococcal vaccine would confer protection during a heterologous epidemic. However, epidemic strain-specific vaccines homologous for class 1 OMP are promising candidates for the control of epidemic serogroup B meningococcal disease.
JAMA.1999;281:1520-1527
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