title: Anti-PsaA and the risk of pneumococcal AOM and carriage.
abstract: Pneumococcal surface adhesin A (PsaA) is one of the common protein antigens of Streptococcus pneumoniae investigated as a possible vaccine candidate on the basis of studies in experimental animal models. The relation between the serum anti-PsaA concentration collected at 6, 12 and 18 months of age and the risk of pneumococcal carriage and acute otitis media (AOM) in the following 6 months was evaluated in 329 children of the Finnish Otitis Media (FinOM) Cohort Study. A higher anti-PsaA concentration at all three time points studied was found to predict a higher risk of pneumococcal carriage 6 months later. A higher anti-PsaA concentration at 6 months also predicted a higher risk of pneumococcal AOM during the following 6 months (RR 1.51, 95% CI 1.24-1.83), whereas a higher anti-PsaA concentration at 12 or 18 months seemed to decrease the risk of pneumococcal AOM (RR 0.94 [95% CI 0.80-1.09] and RR 0.88 [95% CI 0.73-1.07], respectively). These relations remained the same when concomitant risk factors for pneumococcal AOM were included in the models. Previous pneumococcal AOM was the most important risk factor for a subsequent pneumococcal AOM (RR 5.93 [95% CI 2.87-12.3], RR 2.2 [95% CI 1.21-4.00], and RR 3.3 [95% CI 1.72-6.32] during the three periods).
authors.affiliation: Department of Vaccines, National Public Health Institute, Helsinki, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Rapola
authors.forename: Virva
authors.initials: V
authors.lastname: Jäntti
authors.forename: Mervi
authors.initials: M
authors.lastname: Eerola
authors.forename: P Helena
authors.initials: PH
authors.lastname: Mäkelä
authors.forename: Helena
authors.initials: H
authors.lastname: Käyhty
authors.forename: Terhi
authors.initials: T
authors.lastname: Kilpi
mesh_terms: D018829:Adhesins, Bacterial; D000375:Aging / Q000276:immunology; D000907:Antibodies, Bacterial / Q000032:analysis / Q000276:immunology*; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000276:immunology*; D002353:Carrier State / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008074:Lipoproteins / Q000276:immunology*; D016015:Logistic Models; D008297:Male; D026901:Membrane Transport Proteins; D010033:Otitis Media / Q000453:epidemiology* / Q000276:immunology*; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology*; D011237:Predictive Value of Tests; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D008074:Lipoproteins; D026901:Membrane Transport Proteins; C085000:PsaA protein, Streptococcus