title: Pneumococcal conjugate vaccination does not induce a persisting mucosal IgA response in children with recurrent acute otitis media.
abstract: OBJECTIVE
  In a prospective controlled study in young children with a history of recurrent acute otitis media, we analyzed the salivary IgA and IgG antibody titers upon vaccination with a 7-valent pneumococcal conjugate vaccine (PCV) given once or twice, followed by a 23-valent polysaccharide booster vaccination.
  
  
  METHODS
  Salivary IgA and IgG antibody concentrations to vaccine serotype 6B, 14, 18C and 19F were measured by enzyme immunoassay in 38 samples of children vaccinated with PCV and 45 control samples. In the PCV group, 12 samples were taken prior to vaccination, 12 samples 4 weeks after the polysaccharide booster (8 months after the first conjugate vaccination) and 14 samples 7 months after the last vaccination (14 months after the first conjugate vaccination). In the control group 15 children were sampled at each of these three time points.
  
  
  RESULTS
  We observed an increase in salivary IgG antibody concentrations against serotype 6B, 14, and 18C 14 months after the primary vaccination in children vaccinated with PCV twice, although this was significant for serotype 14 only. There was no increase in salivary IgG antibody in children vaccinate with PCV once nor in control children. IgA antibody titers increased significantly after 8 and after 14 months in both the pneumococcal vaccine recipients and the controls. However, the observed increase in mean antibody titers was significantly higher in control children compared to the PCV group.
  
  
  CONCLUSIONS
  We suggest that repeated pneumococcal conjugate vaccination is necessary to induce an increase in salivary IgG antibodies and effectuate clearance of S. pneumoniae from the nasopharyngeal mucosa of children with recurrent acute otitis media. We hypothesize that the increase in salivary IgA is caused by the local boosting of the mucosal immune response by carriage and recurrent infections, which occurs less often in the PCV group compared to the control children.
authors.affiliation: Laboratory of Pediatrics, Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC-Sophia Rotterdam, Room Ee 1500, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Bogaert
authors.forename: R H
authors.initials: RH
authors.lastname: Veenhoven
authors.forename: R
authors.initials: R
authors.lastname: Ramdin
authors.forename: I H T
authors.initials: IH
authors.lastname: Luijendijk
authors.forename: G T
authors.initials: GT
authors.lastname: Rijkers
authors.forename: E A M
authors.initials: EA
authors.lastname: Sanders
authors.forename: R
authors.initials: R
authors.lastname: de Groot
authors.forename: P W M
authors.initials: PW
authors.lastname: Hermans
mesh_terms: D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D018928:Immunity, Mucosal / Q000276:immunology*; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000032:analysis / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis; D007223:Infant; D008297:Male; D010033:Otitis Media / Q000276:immunology*; D022242:Pneumococcal Vaccines / Q000276:immunology*; D012008:Recurrence; D012463:Saliva / Q000276:immunology; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate