title: Impact of the 13-valent pneumococcal conjugate vaccine (pcv13) on invasive pneumococcal disease and carriage in Alaska.
abstract: BACKGROUND
  Alaska Native (AN) children have experienced high rates of invasive pneumococcal disease (IPD). In March 2010, PCV13 was introduced statewide in Alaska. We evaluated the impact of PCV13 on IPD in children and adults, 45 months after introduction.
  
  
  METHODS
  Pneumococcal sterile site isolates, reported through state-wide surveillance, were serotyped using standard methods. We defined a pre-PCV13 time period 2005-2008 and post-PCV13 time period April 2010-December 2013; excluding Jan 2009-March 2010 because PCV13 was introduced pre-licensure in one high-risk region in 2009.
  
  
  RESULTS
  Among Alaska children <5 years, PCV13 serotypes comprised 65% of IPD in the pre-PCV13 period and 26% in the PCV13 period. Among all Alaska children <5 years, IPD rates decreased from 60.9 (pre) to 25.4 (post) per 100,000/year (P<0.001); PCV13 serotype IPD decreased from 37.7 to 6.4 (P<0.001). Among AN children <5 years, IPD rates decreased from 149.2 to 60.8 (P<0.001); PCV13 serotype IPD decreased from 87.0 to 17.4 (P<0.001); non-PCV13 serotype IPD did not change significantly. Among persons 5-17 and ≥45 years, the post-vaccine IPD rate was similar to the baseline period, but declined in persons 18-44 years (39%, P<0.001); this decline was similar in AN and non-AN persons (38%, P=0.016, 43%, P=0.014, respectively).
  
  
  CONCLUSIONS
  Forty-five months after PCV13 introduction, overall IPD and PCV13-serotype IPD rates had decreased 58% and 83%, respectively, in Alaska children <5 years of age when compared with 2005-2008. We observed evidence of indirect effect among adults with a 39% reduction in IPD among persons 18-44 years.
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA. Electronic address: zwa8@cdc.gov.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Bruce
authors.affiliation: Alaska Native Medical Center, Anchorage, AK, USA.
authors.forename: Rosalyn
authors.initials: R
authors.lastname: Singleton
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Bulkow
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Rudolph
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Tammy
authors.initials: T
authors.lastname: Zulz
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Prabhu
authors.initials: P
authors.lastname: Gounder
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Debby
authors.initials: D
authors.lastname: Hurlburt
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Dana
authors.initials: D
authors.lastname: Bruden
authors.affiliation: Arctic Investigations Program, National Center for Emerging Zoonotic and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hennessy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000413:Alaska / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / 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; D055815:Young Adult
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines
keywords: Alaska; Carriage; Invasive pneumococcal disease; Serotype; Streptococcus pneumoniae; US; Vaccine