title: Neonatal protection and preterm birth reduction following maternal group B streptococcus vaccination in a mouse model.
abstract: OBJECTIVE
  Evaluate effects of maternal immunization in a mouse model of Group B Streptococcus (GBS) vaginal colonization using clinical isolates.
  
  
  METHODS
  Female pregnant mice were immunized with heat-killed GBS 21 days before pregnancy and were inoculated intravaginally with GBS cultures (5 × 107CFU twice a day for three days) from the 16th day of pregnancy. Gestation period and mice survival were monitored. Maternal anti-GBS IgG levels have been determined by ELISA analysis in vaccinated, unvaccinated mothers and newborns.
  
  
  RESULTS
  Maternal immunization before pregnancy provided protection to newborns for three of the four GBS strains used. Evaluation of the immunogenicity showed that this vaccination induced higher levels of IgG in vaccinated compared to unvaccinated dams and the presence of antibodies in the offspring at embryonic and postnatal age, and a Th1 response and high levels of IgG2a subclass antibody and IFN-γ were detected. A significant reduction of preterm births was observed in vaccinated mothers (p< 0.05).
  
  
  CONCLUSIONS
  Our finding suggest that vaccinated mothers could protect their progeny from GBS infection and preterm birth through passive immunization. The proposed mouse model may represent a noninvasive and effective tool to investigate pathogenetic mechanisms of GBS ascending infection and for vaccine protection studies.
authors.affiliation: a Centro Servizi Interdipartimentale-STA, University of Rome "Tor Vergata" , Rome , Italy.
authors.forename: R
authors.initials: R
authors.lastname: Bernardini
authors.affiliation: b Division of Neonatology and Neonatal Intensive Care , Casilino General Hospital , Rome , Italy.
authors.forename: R
authors.initials: R
authors.lastname: Aufieri
authors.affiliation: c National Center of Infectious and Parasitic Diseases - NCIPD , Sofia , Bulgaria.
authors.forename: A
authors.initials: A
authors.lastname: Detcheva
authors.affiliation: d Istituto Superiore di Sanità - ISS , Rome , Italy.
authors.forename: S
authors.initials: S
authors.lastname: Recchia
authors.affiliation: a Centro Servizi Interdipartimentale-STA, University of Rome "Tor Vergata" , Rome , Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cicconi
authors.affiliation: e Department of Biomedicine and Prevention , University of Rome "Tor Vergata" , Rome , Italy.|f ProxAgen Ltd., Sofia , Bulgaria.
authors.forename: M
authors.initials: M
authors.lastname: Amicosante
authors.affiliation: g Department of Biology , University of Rome "Tor Vergata" , Rome , Italy.
authors.forename: C
authors.initials: C
authors.lastname: Montesano
authors.affiliation: h Department of Experimental Medicine and Surgery , University of Rome "Tor Vergata" , Rome , Italy.
authors.forename: P
authors.initials: P
authors.lastname: Rossi
authors.affiliation: i University-Hospital Pediatric Department (DPUO), Bambino Gesù Children Hospital , Rome , Italy.
authors.forename: H K
authors.initials: HK
authors.lastname: Tchidjou
authors.affiliation: c National Center of Infectious and Parasitic Diseases - NCIPD , Sofia , Bulgaria.
authors.forename: B
authors.initials: B
authors.lastname: Petrunov
authors.affiliation: d Istituto Superiore di Sanità - ISS , Rome , Italy.
authors.forename: G
authors.initials: G
authors.lastname: Orefici
authors.affiliation: a Centro Servizi Interdipartimentale-STA, University of Rome "Tor Vergata" , Rome , Italy.|g Department of Biology , University of Rome "Tor Vergata" , Rome , Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-0814-8873
authors.initials: M
authors.lastname: Mattei
mesh_terms: D000818:Animals; D021461:Animals, Outbred Strains; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007116:Immunization, Passive; D051379:Mice; D023421:Models, Animal; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000517:prevention & control*; D047928:Premature Birth / Q000276:immunology / Q000517:prevention & control*; D013290:Streptococcal Infections / Q000276:immunology / Q000517:prevention & control*; D013292:Streptococcus agalactiae / Q000276:immunology; D014611:Vaccination / Q000379:methods
keywords: GBS; Intravaginal colonization; murine model; preterm delivery; vaccine