title: Assessment of the direct effectiveness of BC meningococcal vaccine in Rio de Janeiro, Brazil: a case-control study.
abstract: BACKGROUND
  Meningococcal disease is still a serious public health problem in many countries. A vaccine produced by Cuba was the first product against B meningococcus available on a large scale. In an attempt to control the increasing incidence of this serogroup in greater Rio de Janeiro, Brazil, the vaccine was used in 1990 in children aged 6 months-9 years. About 1.6 million children were vaccinated.
  
  
  METHODS
  In order to assess the direct effectiveness of the vaccine in preventing disease, we conducted a case-control study during the first year after vaccination. Using a hospital-based census, we selected all children hospitalized with meningococcal disease and sampled the control group among children hospitalized with other types of meningitis. Vaccine effectiveness was estimated from the relationship, 1-OR, where OR (odds ratio) was the exponential of the logistic regression coefficient for the association between meningococcal disease and previous vaccination.
  
  
  RESULTS
  A total of 275 cases and 279 controls were selected between September 1990 and October 1991. The summary adjusted measure of protection against serogroup B was 54% (95% confidence interval [CI]: 20-74%). Estimated protection varied among different age strata and place of residence, being high among children aged > or = 4 years, 71% (95% CI: 34-87%), and among those who lived in the City of Rio de Janeiro, 74% (95% CI: 42-89%).
  
  
  CONCLUSIONS
  The results suggest that the vaccine produced by Cuba may offer protection against serogroup B meningococcal disease, but its effects may not be homogeneous.
authors.affiliation: Coordenação de Epidemiologia, Secretaria Municipal de Saúde, Rio de Janeiro, Brazil.
authors.forename: C P
authors.initials: CP
authors.lastname: Noronha
authors.forename: C J
authors.initials: CJ
authors.lastname: Struchiner
authors.forename: M E
authors.initials: ME
authors.lastname: Halloran
mesh_terms: D017677:Age Distribution; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D017589:Immunization Programs; D015994:Incidence; D007223:Infant; D016015:Logistic Models; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D009345:Neisseria meningitidis / Q000276:immunology*; D016017:Odds Ratio; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D015397:Program Evaluation; D012111:Residence Characteristics; D012703:Serotyping; D013997:Time Factors
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D011135:Polysaccharides, Bacterial