title: Postvaccination increase in serotype 19A pneumococcal disease in Norway is driven by expansion of penicillin-susceptible strains of the ST199 complex.
abstract: Serotype replacement in invasive pneumococcal disease has been observed after widespread use of the 7-valent pneumococcal conjugate vaccine (PCV7). Replacement is dominated by penicillin-nonsusceptible serotype 19A in several countries. Antibiotic selection pressure has been proposed to interact with immunization, leading to rapid replacement. In Norway, where prescription of antibiotics is limited, post-PCV7 replacement by serotype 19A is dominated by penicillin-susceptible clones. Hence, serotype 19A replacement occurs, although it is not driven by antibiotic selection pressure.
authors.affiliation: Department of Bacteriology and Immunology, Norwegian Institute of Public Health, Oslo, Norway. didrik.frimann.vestrheim@fhi.no
authors.forename: Didrik F
authors.initials: DF
authors.lastname: Vestrheim
authors.forename: Martin
authors.initials: M
authors.lastname: Steinbakk
authors.forename: Ingeborg S
authors.initials: IS
authors.lastname: Aaberge
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Caugant
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D008826:Microbial Sensitivity Tests; D009664:Norway / Q000453:epidemiology; D010406:Penicillins / Q000494:pharmacology*; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D010406:Penicillins; D022242:Pneumococcal Vaccines