title: Pneumococcal serotype distribution in adults with invasive disease and in carrier children in Italy: Should we expect herd protection of adults through infants' vaccination?
abstract: The 7-valent pneumococcal conjugate vaccine (PCV7) produced a significant herd protection in unvaccinated adult population mostly because of pneumococcus carriage decrease in vaccinated children. It is not known if the 13-valent pneumococcal vaccine can give similar effect on adults. Aims of the work were to evaluate whether the 6 additional serotypes are present in nasopharynx of children and serotype distribution in invasive pneumococcal infections (IPD) in adults. Realtime-PCR was used to evaluate pneumococcal serotypes in adults with confirmed IPD and in nasopharyngeal swabs (NP) from 629 children not vaccinated or vaccinated with PCV7 and resident in the same geographical areas. Two hundred twenty-one patients (116 males, median 67.9 years) with IPD were studied (pneumonia n = 103, meningitis n = 61 sepsis n = 50, other n = 7). Two hundred twelve were serotyped. The most frequent serotypes were 3, (31/212; 14.6%), 19A, (19/212; 9.0%), 12 (17/212; 8.0%), 7F, (14/212; 6.6%). In NP of children, the frequency of those serotypes causing over 50% of IPD in adults was very low, ranging from 0.48% for serotype 7F to 7.9% for serotype 19A. On the other side serotype 5, very frequent in NP (18.7%) caused <1% IPD. In conclusion serotypes causing IPD in adults are very rarely found in children NP. We suggest that herd protection obtainable with the additional 6 serotypes included in PCV13 may be more limited than that demonstrated with PCV7 in the past. In order to reduce the burden of disease in adults, adults should be offered a specific vaccination program with highly immunogenic PCV.
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Azzari
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Cortimiglia
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Nieddu
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Moriondo
authors.affiliation: b Pediatric Division; Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Indolfi
authors.affiliation: c Operative Unit of Chemical-Clinical and Microbiological Analysis; Campo di Marte Hospital; ASL2 Lucca , Italy.
authors.forename: Romano
authors.initials: R
authors.lastname: Mattei
authors.affiliation: d Division of Hygiene and Public Health; Invasive Disease Prevention and Surveillance; Prevention Department; ASS5 Friuli , Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Zuliani
authors.affiliation: e Division of Infectious Disease; New Hospital ; Prato , Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Adriani
authors.affiliation: f Microbiology Unit; New Hospital ; Prato , Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Degl'Innocenti
authors.affiliation: g Division of Emergency Unit; New Hospital ; Prato , Italy.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Consales
authors.affiliation: e Division of Infectious Disease; New Hospital ; Prato , Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Aquilini
authors.affiliation: h Division of General Medicine 1; New Hospital ; Prato , Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Bini
authors.affiliation: i Division of General Medicine 2; New Hospital ; Prato , Italy.
authors.forename: Massimo Edoardo
authors.initials: ME
authors.lastname: Di Natale
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Clementina
authors.initials: C
authors.lastname: Canessa
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ricci
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: de Vitis
authors.affiliation: a Division of Immunology; Section of Pediatrics ; Department of Health Sciences; University of Florence and Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Giusi
authors.initials: G
authors.lastname: Mangone
authors.affiliation: j Department of Health Sciences ; University of Florence ; Florence , Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Bechini
authors.affiliation: j Department of Health Sciences ; University of Florence ; Florence , Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonanni
authors.affiliation: k Center for Research and Education of Family Pediatricians (CESPER) ; Padova , Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Pasinato
authors.affiliation: b Pediatric Division; Anna Meyer Children's Hospital ; Florence , Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Resti
mesh_terms: D000328:Adult; D000368:Aged; D002353:Carrier State / Q000382:microbiology* / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D000069443:Heptavalent Pneumococcal Conjugate Vaccine / Q000276:immunology*; D006801:Humans; D032521:Immunity, Herd / Q000276:immunology*; D017589:Immunization Programs; D007558:Italy; D008875:Middle Aged; D009305:Nasopharynx / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000276:immunology*; D011018:Pneumonia, Pneumococcal / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000276:immunology; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000276:immunology*
chemical_list: C538862:13-valent pneumococcal vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Realtime PCR; herd-protection; invasive pneumococcal disease; nasopharyngeal carriage; pneumococcal serotype; vaccine