title: Impact of pneumococcal vaccination in Denmark during the first 3 years after PCV introduction in the childhood immunization programme.
abstract: OBJECTIVE
  The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in Denmark in October 2007 in a 2+1 schedule with a catch-up programme for children up to 17 months of age. To assess the impact of PCV we evaluated on the whole population: (1) direct and indirect effects on incidence of invasive pneumococcal disease (IPD), (2) changes in pneumococcal serotype distribution and (3) IPD related mortality.
  
  
  METHODS
  We compared disease incidence in pre-PCV (years 2000-2007) and PCV periods (years 2008-2010) based on national surveillance data.
  
  
  RESULTS
  In children aged 0-5 years the overall incidence of IPD decreased from 26.7 to 16.3 cases per 100,000 (IRR 0.58; 95% Confidence Interval (CI) [0.48-0.69]) and case fatality declined from 1.8% (12 deaths) in the eight-year pre-PCV period to 0% (no deaths) in the three-year PCV period. In the whole population the overall incidence of IPD and of IPD caused by vaccine serotypes declined significantly from 19.5 to 17.7 and from 7.7 to 3.8 cases per 100,000 persons comparing the two periods. The incidence of IPD due to non-vaccine serotypes (NVT-IPD) increased significantly from 11.8 to 13.9 cases per 100,000 in the whole population (incidence rate ratio 1.18; 95% CI [1.12-1.24]) with predominance of the serotypes 1.7F and 19A.
  
  
  CONCLUSIONS
  We report a marked decline in incidence in IPD in both vaccinated and non-vaccinated age groups and a minor but statistically significant increase in incidence of IPD due to NVTs in both vaccinated and non-vaccinated groups with predominance of serotypes covered by higher valence pneumococcal conjugate vaccines.
authors.affiliation: Neisseria and Streptococcus Reference Laboratory, Department of Microbiological Surveillance and Research, Statens Serum Institut (SSI), Copenhagen, Denmark. HIG@ssi.dk, helene ingels@yahoo.dk
authors.forename: Helene
authors.initials: H
authors.lastname: Ingels
authors.forename: Jeppe
authors.initials: J
authors.lastname: Rasmussen
authors.forename: Peter Henrik
authors.initials: PH
authors.lastname: Andersen
authors.forename: Zitta B
authors.initials: ZB
authors.lastname: Harboe
authors.forename: Steffen
authors.initials: S
authors.lastname: Glismann
authors.forename: Helle
authors.initials: H
authors.lastname: Konradsen
authors.forename: Steen
authors.initials: S
authors.lastname: Hoffmann
authors.forename: Palle
authors.initials: P
authors.lastname: Valentiner-Branth
authors.forename: Lotte
authors.initials: L
authors.lastname: Lambertsen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D017589:Immunization Programs / Q000706:statistics & numerical data*; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines