title: Pneumococcal conjugate vaccine herd effects on non-invasive pneumococcal pneumonia in elderly.
abstract: Herd protection from infant pneumococcal conjugate vaccination is well established for invasive pneumococcal disease (IPD) but not for non-IPD pneumococcal community-acquired pneumonia (PCAP). We assessed the contribution of vaccine-serotypes in non-IPD PCAP in adults 65 years and older in the period 2008-2013.
  
  
  
  This is a post hoc analysis of two prospective studies from the Netherlands. Serotype specific urinary antigen detection and routine microbiological testing were used to categorize episodes as IPD or non-IPD PCAP caused by 7-valent pneumococcal conjugate vaccine (PCV7), PCV10-7 (three additional PCV10 serotypes), PCV13-10 (three additional PCV13 serotypes), and non-PCV13 serotypes. Proportions per vaccine-serotype group were assessed per year from June 1st to May 31st. Time trends were compared to national IPD data.
  
  
  
  Of 270 non-IPD PCAP episodes with known serotype, PCV7 serotypes decreased from 28% in 2008/2009 to 7% in 2012/2013 (p-value for trend <0.001). No change in PCV10-7 (19% overall) and PCV13-10 (29% overall) serotypes was observed. Non-PCV13 serotypes increased from 30% in 2008/2009 to 37% in 2012/2013 (p-value for trend 0.048). Trends corresponded with national IPD data.
  
  
  
  PCV7 serotypes declined in non-IPD PCAP among elderly between 2008 and 2013, comparable to IPD data. No reduction in the additional PCV10 serotypes could be demonstrated within the first two years after PCV10 introduction.
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. Electronic address: c.h.vanwerkhoven@umcutrecht.nl.
authors.forename: Cornelis H
authors.initials: CH
authors.lastname: van Werkhoven
authors.affiliation: Pfizer Inc. (Former Employee), 500 Arcola Rd, Collegeville, PA 19426, USA.
authors.forename: Rosalind C
authors.initials: RC
authors.lastname: Hollingsworth
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; Department of Respiratory Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
authors.forename: Susanne M
authors.initials: SM
authors.lastname: Huijts
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
authors.forename: Marieke
authors.initials: M
authors.lastname: Bolkenbaas
authors.affiliation: Pfizer Vaccine Clinical Research, Vanwall Rd, Maidenhead SL6 4UB, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Webber
authors.affiliation: Pfizer Vaccine Clinical Research, 500 Arcola Rd, Collegeville, PA 19426, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Patterson
authors.affiliation: Department of Paediatric Immunology and Infectious Diseases, University Medical Center Utrecht Wilhelmina Children's Hospital, Lundlaan 6, 3584 EA Utrecht, The Netherlands.
authors.forename: Elisabeth A M
authors.initials: EA
authors.lastname: Sanders
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
authors.forename: Marc J M
authors.initials: MJ
authors.lastname: Bonten
mesh_terms: D000368:Aged; D017714:Community-Acquired Infections / Q000382:microbiology / Q000517:prevention & control*; D000069443:Heptavalent Pneumococcal Conjugate Vaccine / Q000627:therapeutic use*; D006801:Humans; D032521:Immunity, Herd; D009426:Netherlands / Q000453:epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000627:therapeutic use; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology / Q000517:prevention & control*; D011446:Prospective Studies; D065288:Serogroup
chemical_list: C586648:10-valent pneumococcal conjugate vaccine; C538862:13-valent pneumococcal vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines
keywords: Herd protection; Invasive pneumococcal disease; Pneumococcal conjugate vaccine; Pneumococcal pneumonia