title: Antibody persistence and immunologic memory in children vaccinated with 4 doses of pneumococcal conjugate vaccines: Results from 2 long-term follow-up studies.
abstract: To investigate long-term antibody persistence following the administration of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), we present results of 2 follow-up studies assessing antibody persistence following 2 3+1 schedules up to 4 (NCT00624819 - Study A) and 5 years (NCT00891176 - Study B) post-booster vaccination. In Study A, antibody persistence was measured one, 2 and 4 years post-booster in children previously primed and boosted with PHiD-CV, or primed with the 7-valent pneumococcal conjugate vaccine (7vCRM) and boosted with either PHiD-CV or 7vCRM. In Study B, PHiD-CV was co-administered with meningococcal vaccines, and pneumococcal antibody persistence was measured 2, 3 and 5 years post-booster. An age-matched control group, unvaccinated against Streptococcus pneumoniae, was enrolled in Study A, allowing assessment of immunologic memory by administration of one dose of PHiD-CV to both primed (4 years post-booster) and unprimed 6-year-old children. Four years post-booster (Study A), antibody concentrations and opsonophagocytic activity (OPA) titers remained higher compared to the pre-booster timepoint, with no major differences between the 3 primed groups. Antibody persistence was also observed in Study B, with minimal differences between groups. The additional PHiD-CV dose administered 4 years post-booster in Study A elicited more robust immune responses in primed children than in unprimed children. Long-term serotype-specific antibody persistence and robust immunologic memory responses observed in these 2 studies suggest induction of long-term protection against pneumococcal disease after PHiD-CV vaccination.
authors.affiliation: a Department of Preventive Medicine , Poznan University School of Medical Sciences , Poznan , Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Wysocki
authors.affiliation: b Pediatrics Department , Zespol Opieki Zdrowotnej w Debicy , Debica , Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Brzostek
authors.affiliation: c Neuro-infection and Pediatric Neurology , John Paul II Hospital , Cracow , Poland.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Konior
authors.affiliation: d Gemeinschaftspraxis für Kinder- und Jugendmedizin , Mannheim , Germany.
authors.forename: Falko G
authors.initials: FG
authors.lastname: Panzer
authors.affiliation: e GSK , Wavre , Belgium.
authors.forename: Nancy A
authors.initials: NA
authors.lastname: François
authors.affiliation: f GSK , Bangalore , India.
authors.forename: Sudheer M
authors.initials: SM
authors.lastname: Ravula
authors.affiliation: f GSK , Bangalore , India.
authors.forename: Devayani A
authors.initials: DA
authors.lastname: Kolhe
authors.affiliation: e GSK , Wavre , Belgium.
authors.forename: Yue
authors.initials: Y
authors.lastname: Song
authors.affiliation: e GSK , Wavre , Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: Dieussaert
authors.affiliation: e GSK , Wavre , Belgium.
authors.forename: Lode
authors.initials: L
authors.lastname: Schuerman
authors.affiliation: e GSK , Wavre , Belgium.
authors.forename: Dorota
authors.initials: D
authors.lastname: Borys
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007156:Immunologic Memory; D007223:Infant; D008297:Male; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; C547294:PHiD-CV vaccine; D022242:Pneumococcal Vaccines
keywords: Streptococcus pneumoniae; antibody persistence; children; immunologic memory; pneumococcal conjugate vaccine