Effect of the 13-valent pneumococcal conjugate vaccine on nasopharyngeal colonization by Streptococcus pneumoniae--Alaska, 2008-2012

J Infect Dis. 2014 Apr 15;209(8):1251-8. doi: 10.1093/infdis/jit642. Epub 2013 Nov 23.

Abstract

Background: In 2010, a 13-valent pneumococcal conjugate vaccine (PCV13) replaced a 7-valent vaccine (PCV7) that contained all PCV7 serotypes plus 6 additional serotypes (PCV6+). We conducted annual surveys from 2008 to 2012 to determine the effect of PCV13 on colonization by pneumococcal serotypes.

Methods: We obtained nasopharyngeal swabs for pneumococcal identification and serotyping from residents of all ages at 8 rural villages and children age <60 months at 2 urban clinics. We conducted interviews/medical records review for all participants.

Results: A total of 18 207 nasopharyngeal swabs (rural = 16 098; urban = 2109) were collected. From 2008 to 2012, 84% of rural and 90% of urban children age <5 years were age-appropriately vaccinated with a PCV. Overall pneumococcal colonization prevalence remained stable among rural (66%) and urban (35%) children age <5 years, and adults age ≥18 years (14%). Colonization by PCV6+ serotypes declined significantly among rural children age <5 years, urban children age <5, and adults age ≥18 over the course of the study (25%-5%, 22%-9%, 22%-6%, respectively).

Conclusions: PCV13 was rapidly introduced into the Alaska childhood immunization schedule and reduced colonization by PCV6+ serotypes among children. Unvaccinated adults also experienced comparable reductions in vaccine serotype colonization indicating substantial indirect protection from PCV13.

Keywords: Alaska; Alaska Native people; Streptococcus pneumoniae; conjugate vaccine; nasopharyngeal colonization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Alaska / epidemiology
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Male
  • Nasopharyngeal Diseases / epidemiology
  • Nasopharyngeal Diseases / microbiology
  • Nasopharyngeal Diseases / prevention & control*
  • Nasopharynx / microbiology*
  • Pneumococcal Infections / epidemiology
  • Pneumococcal Infections / microbiology
  • Pneumococcal Infections / prevention & control*
  • Pneumococcal Vaccines / administration & dosage*
  • Prevalence
  • Rural Population
  • Streptococcus pneumoniae / isolation & purification*
  • Urban Population
  • Vaccination

Substances

  • 13-valent pneumococcal vaccine
  • Pneumococcal Vaccines