title: Influence of respiratory viruses on the evaluation of the 13-valent pneumococcal conjugate vaccine effectiveness in children under 5 years old: A time-series study for the 2001-2013 period.
abstract: S treptococcus pneumoniae is the main agent in bacterial consolidated pneumonias. In 2012, the 13-valent pneumococcal conjugate vaccine was introduced in the Argentine national immunization schedule for immunocompetent children as of two months old with a two-dose schedule plus a booster.
  
  
  
  To analyze the influence of respiratory viruses on the evaluation of the 13-valent pneumococcal conjugate vaccine effectiveness in relation to the number of hospitalizations for radiologically-confirmed consolidated pneumonias (RCCP).
  
  
  
  Observational, analytical, time-series study. All children hospitalized with a diagnosis of RCCP as per the World Health Organization's criteria between March and November throughout the2001-2013period were included. Viral diagnosis (respiratory syncytial virus, adenovirus, influenza and parainfluenza) was performed by indirect immunofluorescence using nasopharyngeal aspirates or by reverse transcription polymerase chain reaction. Time-series were developed to compare preimmunization 2001-2011 and post-immunization 2012-2013 periods.
  
  
  
  Out of a total of 11,306 children under 5 years old with acute lower respiratory tract infections, 4974 with RCCP were included. Annual average number of hospitalizations for RCCP: 394.8 pre-immunization, 315.5 post-immunization (reduction of 20.1%, 95% confidence interval |-CI-|: 13.13-26.49%, p < 0.001). Annual average number of hospitalizations for non-viral RCCP: 255.5 pre-immunization, 183 post-immunization (reduction of 28.4%, 95% CI: 20.5-35.78%, p < 0.001). Annual average number of hospitalizations for viral RCCP: 139.2 pre-immunization, 132 post-immunization (reduction of 4.8%, 95% CI: 8.38-16.49%, p= 0.4758). The proportion of RCCP with positive viral diagnosis was 35.3 % pre-immunization and 42% post-immunization (p= 0.001).
  
  
  
  An overall significant reduction in the number of hospitalizations for RCCP was observed following the introduction of the 13-valent pneumococcal conjugate vaccine, especially in the case of non-viral pneumonias. It is critical to continue with the epidemiological surveillance to evaluate the impact of this intervention and viral behavior in relation to RCCP.
authors.affiliation: División Promoción y Protección de la Salud, Hospital de Niños Ricardo Gutiérrez, Ciudad Autónoma de Buenos Aires.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Gentile
authors.affiliation: División Promoción y Protección de la Salud, Hospital de Niños Ricardo Gutiérrez, Ciudad Autónoma de Buenos Aires.
authors.forename: María del Valle
authors.initials: Mdel V
authors.lastname: Juarez
authors.affiliation: División Promoción y Protección de la Salud, Hospital de Niños Ricardo Gutiérrez, Ciudad Autónoma de Buenos Aires.
authors.forename: María Florencia
authors.initials: MF
authors.lastname: Luciön
authors.affiliation: División Promoción y Protección de la Salud, Hospital de Niños Ricardo Gutiérrez, Ciudad Autónoma de Buenos Aires.
authors.forename: Viviana Sandra
authors.initials: VS
authors.lastname: Romanin
authors.affiliation: División Promoción y Protección de la Salud, Hospital de Niños Ricardo Gutiérrez, Ciudad Autónoma de Buenos Aires.
authors.forename: Norberto
authors.initials: N
authors.lastname: Giglio
authors.affiliation: División Promoción y Protección de la Salud, Hospital de Niños Ricardo Gutiérrez, Ciudad Autónoma de Buenos Aires.
authors.forename: Julia
authors.initials: J
authors.lastname: Bakin
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D000071497:Immunogenicity, Vaccine; D007223:Infant; D008297:Male; D022242:Pneumococcal Vaccines / Q000276:immunology*; D011024:Pneumonia, Viral / Q000276:immunology*; D018074:Vaccines, Conjugate
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate