title: Decreased Incidence of Respiratory Infections in Children After Vaccination with Ten-valent Pneumococcal Vaccine.
abstract: BACKGROUND
  Respiratory tract infections (RTIs) and antibiotic usage are common in children, increasing the risk of antibacterial resistance. The introduction of protein-conjugated pneumococcal vaccines has led to reduction in pneumococcal infections. In 2011, pneumococcal protein-conjugated vaccine-10 was introduced into the national childhood vaccination in Iceland, a population not earlier vaccinated against pneumococcus, with 95% vaccine uptake in the first year. The aim of the study was to evaluate the number of children visiting the Children's Hospital Iceland for RTIs before and after the introduction of the vaccine.
  
  
  METHODS
  Admissions and visits to the Children's Hospital because of RTIs were recorded, and children aged 3 months to 2 years in the nonvaccine eligible cohort (born 2008-2010) were compared with the vaccine eligible cohort (born in 2011). Statistical analysis was done using large sample Z test and incidence rate ratios (IRRs) were calculated.
  
  
  RESULTS
  A significant reduction in incidence rate was found when comparing the nonvaccine eligible cohort with the vaccine eligible cohort, both for acute otitis media (AOM) (IRR: 0.76; 95% confidence interval: 0.67-0.87; P < 0.0001) and for pneumonia (IRR: 0.77; 95% confidence interval: 0.64-0.95; P < 0.01).
  
  
  CONCLUSIONS
  A significant reduction in hospital visits because of AOM and pneumonia in children vaccinated with pneumococcal protein-conjugated vaccine-10 was established. The abrupt and significant reduction of AOM is unusually clear. This reduction was noted very early after initiation of the vaccination.
authors.affiliation: From the *Faculty of Medicine, University of Iceland, Reykjavik, Iceland; †Department of Clinical Microbiology, Landspitali University Hospital, Reykjavik, Iceland; ‡Department of Mathematics, University of Iceland, Reykjavik, Iceland; and §Children's Hospital Iceland, University Hospital - Landspítali, Reykjavik, Iceland.
authors.forename: Samuel
authors.initials: S
authors.lastname: Sigurdsson
authors.forename: Karl G
authors.initials: KG
authors.lastname: Kristinsson
authors.forename: Helga
authors.initials: H
authors.lastname: Erlendsdóttir
authors.forename: Birgir
authors.initials: B
authors.lastname: Hrafnkelsson
authors.forename: Ásgeir
authors.initials: Á
authors.lastname: Haraldsson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines; D012189:Retrospective Studies; D013296:Streptococcus pneumoniae
chemical_list: D022242:Pneumococcal Vaccines