title: Indirect cohort analysis of 10-valent pneumococcal conjugate vaccine effectiveness against vaccine-type and vaccine-related invasive pneumococcal disease.
abstract: We applied the indirect cohort method to estimate effectiveness of 10-valent pneumococcal conjugate vaccine (PCV10) among young children in Brazil. Cases of invasive pneumococcal disease (IPD), i.e., Streptococcus pneumoniae, detected in normally sterile fluid identified through laboratory-based surveillance and previously enrolled in a matched case-control effectiveness study are included. We estimated PCV10 effectiveness using multivariable logistic regression comparing PCV10 vaccination among children with vaccine-type or vaccine-related IPD vs. children with non-vaccine-type disease. The adjusted effectiveness of ≥ 1 doses against vaccine-type (72.8%, 95% confidence interval [CI] [44.1, 86.7]) and vaccine-related (61.3%, 95%CI [14.5, 82.5]) IPD were similar to the effectiveness observed in the original case-control study (which required enrollment >1200 controls). We also found significant protection of ≥ 1 dose against individual vaccine serotypes (14, 6B, 23F, 18C) and against vaccine-related serotype 19A. The indirect cohort methods leverages existing surveillance is a feasible approach for evaluating pneumococcal conjugate vaccines, particularly in resource-limited settings.
authors.affiliation: National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia. Electronic address: jverani@cdc.gov.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Verani
authors.affiliation: National Immunization Program, Secretariat for Health Surveillance, Ministry of Health, Brasília, Brazil; Center for Tropical Medicine, University of Brasília, Brasília, Brazil.
authors.forename: Carla Magda A Santos
authors.initials: CM
authors.lastname: Domingues
authors.affiliation: Department of Social Medicine, School of Medical Sciences of Santa Casa, São Paulo, Brazil.
authors.forename: José Cassio
authors.initials: JC
authors.lastname: de Moraes
mesh_terms: D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008586:Meningitis, Pneumococcal / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000302:isolation & purification*; D016896:Treatment Outcome
chemical_list: C586648:10-valent pneumococcal conjugate vaccine; D022242:Pneumococcal Vaccines
keywords: Brazil; Case-control studies; Invasive pneumococcal disease (IPD); Pneumococcal conjugate vaccine (PCV); Vaccine effectiveness