title: Epidemiologic evidence for serotype-specific acquired immunity to pneumococcal carriage.
abstract: Nasopharyngeal carriage of Streptococcus pneumoniae is required for transmission of the bacteria and for invasive disease. There have been conflicting reports as to whether protection against carriage is serotype specific and which immune mechanisms drive carriage. Analyzing longitudinal carriage data from Israeli toddlers in day care, we found a lower risk of colonization with types 6A, 14, and 23F after previous exposure to the homologous type. Nonsignificant trends suggesting possible protection derived from prior exposure were found for types 19A and 23A. Furthermore, we found that, for types 14 and 23F, this specific protection correlated with increased serotype-specific antibody concentration. We found no evidence of specific protection for type 6B, group 15, or type 19F. Our findings imply that at least some serotypes generate anti-capsular antibodies that can reduce the risk of carriage in unimmunized toddlers.
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115, USA. dweinber@fas.harvard.edu
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Weinberger
authors.forename: Ron
authors.initials: R
authors.lastname: Dagan
authors.forename: Noga
authors.initials: N
authors.lastname: Givon-Lavi
authors.forename: Gili
authors.initials: G
authors.lastname: Regev-Yochay
authors.forename: Richard
authors.initials: R
authors.lastname: Malley
authors.forename: Marc
authors.initials: M
authors.lastname: Lipsitch
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D016667:Bacterial Capsules / Q000276:immunology; D002353:Carrier State / Q000276:immunology*; D002656:Child Day Care Centers; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007557:Israel; D008137:Longitudinal Studies; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000907:Antibodies, Bacterial