title: Impact on respiratory tract infections of heptavalent pneumococcal conjugate vaccine administered at 3, 5 and 11 months of age.
abstract: BACKGROUND
  Medical and public health importance of pneumococcal infections justifies the implementation of measures capable of reducing their incidence and severity, and explains why the recently marketed heptavalent pneumococcal conjugate vaccine (PCV-7) has been widely studied by pediatricians. This study was designed to evaluate the impact of PCV-7 administered at 3, 5 and 11 months of age on respiratory tract infections in very young children.
  
  
  METHODS
  A total of 1,571 healthy infants (910 males) aged 75-105 days (median 82 days) were enrolled in this prospective cohort trial to receive a hexavalent vaccine (DTaP/IPV/HBV/Hib) and PCV-7 (n = 819) or the hexavalent vaccine alone (n = 752) at 3, 5 and 11 months of age. Morbidity was recorded for the 24 months following the second dose by monthly telephone interviews conducted by investigators blinded to the study treatment assignment using standardised questionnaires. During these interviews, the caregivers and the children's pediatricians were questioned about illnesses and the use of antibiotics since the previous telephone call. All of the data were analysed using SAS Windows v.12.
  
  
  RESULTS
  Among the 1,555 subjects (98.9%) who completed the study, analysis of the data by the periods of follow-up demonstrated that radiologically confirmed community-acquired pneumonia (CAP) was significantly less frequent in the PCV-7 group during the follow-up as a whole and during the last period of follow-up. Moreover, there were statistically significant between-group differences in the incidence of acute otitis media (AOM) in each half-year period of follow-up except the first, with significantly lower number of episodes in children receiving PCV-7 than in controls. Furthermore, the antibiotic prescription data showed that the probability of receiving an antibiotic course was significantly lower in the PCV-7 group than in the control group.
  
  
  CONCLUSIONS
  Our findings show the effectiveness of the simplified PCV-7 schedule (three doses administered at 3, 5 and 11-12 months of age) in the prevention of CAP and AOM, diseases in which Streptococcus pneumoniae plays a major etiological role. A further benefit is that the use of PCV-7 reduces the number of antibiotic prescriptions. All of these advantages may also be important from an economic point of view.
authors.affiliation: Institute of Pediatrics, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy. susanna.esposito@unimi.it
authors.forename: Susanna
authors.initials: S
authors.lastname: Esposito
authors.forename: Alessandro
authors.initials: A
authors.lastname: Lizioli
authors.forename: Annalisa
authors.initials: A
authors.lastname: Lastrico
authors.forename: Enrica
authors.initials: E
authors.lastname: Begliatti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Rognoni
authors.forename: Claudia
authors.initials: C
authors.lastname: Tagliabue
authors.forename: Laura
authors.initials: L
authors.lastname: Cesati
authors.forename: Vittorio
authors.initials: V
authors.lastname: Carreri
authors.forename: Nicola
authors.initials: N
authors.lastname: Principi
mesh_terms: D015331:Cohort Studies; D004334:Drug Administration Schedule; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage*; D017063:Outcome Assessment, Health Care; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D011018:Pneumonia, Pneumococcal / Q000401:mortality* / Q000517:prevention & control*; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022401:Meningococcal Vaccines; D022242:Pneumococcal Vaccines