title: Immunogenicity and safety of a second administration of 13-valent pneumococcal conjugate vaccine 5 years after initial vaccination in adults 50 years and older.
abstract: Vaccination effectively reduces invasive disease and pneumonia caused by Streptococcus pneumoniae. However, waning antibody titers and the ability of revaccination to boost titers in older adults have been concerns. A study to describe antibody persistence after vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) and response to revaccination 5 years after the initial dose was conducted.
  
  
  
  Pneumococcal vaccine-naive subjects aged 50-59 years were randomized and vaccinated with PCV13 plus trivalent inactivated influenza vaccine concomitantly or 1 month apart, then revaccinated with PCV13 five years later. Antipneumococcal polysaccharide opsonophagocytic activity (OPA) geometric mean titers (GMTs) and immunoglobulin G (IgG) geometric mean concentrations (GMCs) were determined before and approximately 1 month after each vaccination. Targeted local reactions and systemic events were collected for 14 days, adverse events (AEs) for 1 month, and serious AEs (SAEs) for 6 months after each vaccination.
  
  
  
  Of 1116 randomized subjects, 727 were revaccinated at year 5. Between the time of initial vaccination and revaccination, OPA GMTs and IgG GMCs declined but remained higher than levels before initial vaccination for 12 of the 13 vaccine serotypes. One month after revaccination, OPA GMTs and IgG GMCs were comparable with, or higher than, levels observed 1 month after initial vaccination for most vaccine serotypes. Local reactions were mostly mild. AEs were reported by <5% and SAEs by <1% of subjects at 1 and 6 months after revaccination, respectively. No SAEs were vaccine-related.
  
  
  
  Revaccination of adults ≥50 years with PCV13 five years after primary vaccination was safe and immunogenic. Additionally, antibody titers were maintained for at least 5 years after vaccination. The vaccine stimulated a memory response as shown by enhanced responses that were maintained or enhanced by revaccination. CLINICALTRIALS.
  
  
  
  NCT00521586.
authors.affiliation: Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. Electronic address: Robert.Frenck@cchmc.org.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Frenck
authors.affiliation: Pfizer Vaccines Research, Pfizer Ltd, Walton Oaks, Dorking Road, Tadworth, Surrey, KT20 7NS, UK. Electronic address: anne.fiquet@pfizer.com.
authors.forename: Anne
authors.initials: A
authors.lastname: Fiquet
authors.affiliation: Pfizer Vaccines Research, Pfizer Inc, 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: alejandra.gurtman@pfizer.com.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Gurtman
authors.affiliation: Cary Medical Research, Cary, NC, USA. Electronic address: mvancleeff@carymedicalgroup.com.
authors.forename: Martin
authors.initials: M
authors.lastname: van Cleeff
authors.affiliation: Rochester Clinical Research, Rochester, NY, USA. Electronic address: mdavis@rcrclinical.com.
authors.forename: Matthew
authors.initials: M
authors.lastname: Davis
authors.affiliation: Raleigh Medical Group, 3521 Haworth Dr, Raleigh, NC, USA. Electronic address: jrubino@pmg-research.com.
authors.forename: John
authors.initials: J
authors.lastname: Rubino
authors.affiliation: Volunteer Research Group at The University of Tennessee Medical Center, Knoxville, TN, USA. Electronic address: wbsmd@noccr.com.
authors.forename: William
authors.initials: W
authors.lastname: Smith
authors.affiliation: inVentiv Health Clinical, LLC, 504 Carnegie Center, Princeton, NJ 08540, USA. Electronic address: Vani.Sundaraiyer@inventivhealth.com.
authors.forename: Vani
authors.initials: V
authors.lastname: Sundaraiyer
authors.affiliation: Pfizer Vaccines Research, Pfizer Inc, 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: mohinderjitsidhu@yahoo.com.
authors.forename: Mohinder
authors.initials: M
authors.lastname: Sidhu
authors.affiliation: Pfizer Vaccines Research, Pfizer Inc, 401 North Middletown Road, Pearl River, NY 10965, USA. Electronic address: Emilio.Emini@gatesfoundation.org.
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Emini
authors.affiliation: Pfizer Vaccines 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: Pfizer Vaccines 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
authors.affiliation: Pfizer Vaccines Research, Pfizer GmbH, Linkstraße 10, 10785 Berlin, Germany. Electronic address: Beate.Schmoele-Thoma@Pfizer.com.
authors.forename: Beate
authors.initials: B
authors.lastname: Schmoele-Thoma
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D000071497:Immunogenicity, Vaccine; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D007252:Influenza Vaccines / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: C538862:13-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007252:Influenza Vaccines; D022242:Pneumococcal Vaccines
keywords: Adults; PCV13; Pneumococcal conjugate vaccine; Recall responses; Revaccination