title: Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine administered to older infants and children naïve to pneumococcal vaccination.
abstract: BACKGROUND
  Streptococcus pneumoniae infections are a major cause of morbidity and mortality in children <5 years old worldwide. To increase serotype coverage globally, a 13-valent pneumococcal conjugate vaccine (PCV13) has been developed and approved in many countries worldwide.
  
  
  OBJECTIVE
  Assess the safety and immunogenicity of PCV13 in healthy older infants and children naïve to previous pneumococcal vaccination.
  
  
  METHODS
  This was a phase 3, open-label, multicenter study conducted in Polish children (N=354) who were vaccinated according to 3 age-appropriate catch-up schedules: Group 1 (aged 7 to <12 months) received two PCV13 doses with a booster at 12-16 months of age; Group 2 (aged 12 to <24 months) received two vaccine doses only; and Group 3 (aged 24 to <72 months) received a single dose of PCV13. Statistical analyses were descriptive. The proportion of immunological "responders" achieving serotype-specific antipneumococcal polysaccharide concentrations ≥0.35μg/mL, 1-month after the last dose of vaccine, was determined for each vaccine serotype. In addition, antipolysaccharide immunoglobulin (Ig) G geometric mean concentrations (GMCs) were calculated. Safety assessments included systemic and local reactions, and adverse events.
  
  
  RESULTS
  The proportion of immunological responders was ≥88% across groups for all serotypes. Antipolysaccharide IgG GMCs were generally similar across groups. Each schedule elicited immune response levels against all 13 serotypes comparable to or greater than levels previously reported in infants after a 3-dose series. The 3 catch-up schedules had similar tolerability and safety profiles; a trend was present towards greater local tenderness with increasing age and subsequent dose administration.
  
  
  CONCLUSIONS
  Immunological responses and safety results support the use of PCV13 for catch-up schedules in older infants and children naïve to pneumococcal vaccination.
authors.affiliation: Department of Preventive Medicine, Poznan University of Medical Sciences, ul. Smoluchowskiego 11, 60-179 Poznan, Poland. Electronic address: jwysocki@ump.edu.pl.
authors.forename: Jacek
authors.initials: J
authors.lastname: Wysocki
authors.affiliation: NZOZ w Debicy, Poradnia, Debica, Poland. Electronic address: jerzy_br@poczta.onet.pl.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Brzostek
authors.affiliation: NZOZ Praktyka Lekarza, Rodzinnego Alina Grocka-Wlaźlak, Oborniki Śląskie, Poland. Electronic address: henryktomasz@poczta.onet.pl.
authors.forename: Henryk
authors.initials: H
authors.lastname: Szymański
authors.affiliation: NZOZ Salmed, Poradnia, Leczna, Poland. Electronic address: salmed@salmed.eu.
authors.forename: Bogusław
authors.initials: B
authors.lastname: Tetiurka
authors.affiliation: Department of Paediatric Allergology, Gastroenterology and Nutrition, Medical University of Lodz, Lodz, Poland. Electronic address: etka@op.pl.
authors.forename: Ewa
authors.initials: E
authors.lastname: Toporowska-Kowalska
authors.affiliation: Department of Paediatric Allergology, Gastroenterology and Nutrition, Medical University of Lodz, Lodz, Poland. Electronic address: etka@csk.am.lodz.pl.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Wasowska-Królikowska
authors.affiliation: Pfizer Inc., 500 Arcola Road, Collegeville, PA, USA. Electronic address: dasarkozy@verizon.net.
authors.forename: Denise A
authors.initials: DA
authors.lastname: Sarkozy
authors.affiliation: Vaccine Clinical Research, Pfizer Inc., 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: peter.giardina@pfizer.com.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Giardina
authors.affiliation: Vaccine Clinical Research, Pfizer Inc., 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: bill.gruber@pfizer.com.
authors.forename: William C
authors.initials: WC
authors.lastname: Gruber
authors.affiliation: Vaccine Clinical Research, Pfizer Inc., 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: Emilio.emini@pfizer.com.
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Emini
authors.affiliation: Vaccine Clinical Research, Pfizer Inc., 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: dan.scott@pfizer.com.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Scott
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D011008:Pneumococcal Infections / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D011044:Poland; D013296:Streptococcus pneumoniae / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: C538862:13-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Immunization; Immunogenicity; Pneumococcal conjugate vaccine; Vaccine clinical evaluation