title: Maternal Immunization With an Investigational Trivalent Group B Streptococcal Vaccine: A Randomized Controlled Trial.
abstract: OBJECTIVE
  To evaluate the safety and immunogenicity of an investigational trivalent group B streptococcal vaccine in pregnant women and antibody transfer to their newborns.
  
  
  METHODS
  The primary outcome of this observer-blind, randomized study was to estimate placental antibody transfer rates at birth. Secondary outcomes included measurement of serotype-specific antibodies at screening, 30 days postvaccination, at delivery, and 91 days postpartum, infant antibody levels at 3 months of age, the potential effect on routine infant diphtheria vaccination at 1 month after the third infant series dose, and safety in mother and infant participants through at least 5 months postpartum. Sample size was based on 60 participants in the vaccine group giving a probability of observing at least one adverse event of 90% if the actual rate of the event was 3.8%.
  
  
  RESULTS
  From September 2011 to October 2013, 86 pregnant women were allocated in a 3:2 ratio to receive an investigational group B streptococcal vaccine containing glycoconjugates of serotypes Ia, Ib, and III or placebo. Demographics were similar across groups. Transfer ratios were 66-79% and maternal geometric mean concentrations increased 16-, 23-, and 20-fold by delivery against serotypes Ia, Ib, and III, respectively, Women with no detectable antibodies at inclusion had lower responses than those with detectable antibodies. Three months after birth, infant antibody concentrations were 22-25% of birth levels. Antidiphtheria geometric mean concentrations were similar across groups. In the vaccine and placebo groups, 32 of 51 women (63%) and 26 of 35 women (74%) reported adverse effects, respectively.
  
  
  CONCLUSIONS
  The investigational vaccine was well-tolerated without safety signals in recipients and their infants or interference with routine infant diphtheria vaccination, although further studies on safety and effectiveness are needed. The investigational vaccine was immunogenic for all serotypes, particularly among women with detectable antibody levels at baseline. Antibody transfer to neonates was at similar levels to other maternally administered polysaccharide vaccines.
  
  
  BACKGROUND
  ClinicalTrials.gov, www.clinicaltrials.gov, NCT01446289.
authors.affiliation: Femicare Clinical Research for Women and the Department of Obstetrics and Gynecology, Regional Hospital H Hart, Tienen, University Hospital Antwerpen, Antwerp, and the Department of Obstetrics and Gynaecology, University Hospitals KULeuven, Leuven, Belgium; the Canadian Center for Vaccinology, Department of Pediatrics and Microbiology and Immunology, IWK Health Centre and Dalhousie University, Halifax, Nova Scotia, Canada; GlaxoSmithKline LLC, Cambridge, Massachusetts; and Novartis Vaccines and Diagnostics S.r.l, Siena, Italy-a GSK company.
authors.forename: Gilbert G G
authors.initials: GG
authors.lastname: Donders
authors.forename: Scott A
authors.initials: SA
authors.lastname: Halperin
authors.forename: Roland
authors.initials: R
authors.lastname: Devlieger
authors.forename: Sherryl
authors.initials: S
authors.lastname: Baker
authors.forename: Pietro
authors.initials: P
authors.lastname: Forte
authors.forename: Frederick
authors.initials: F
authors.lastname: Wittke
authors.forename: Karen S
authors.initials: KS
authors.lastname: Slobod
authors.forename: Peter M
authors.initials: PM
authors.lastname: Dull
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007114:Immunization; D007231:Infant, Newborn; D011247:Pregnancy; D013290:Streptococcal Infections / Q000517:prevention & control*; D022541:Streptococcal Vaccines; D013292:Streptococcus agalactiae / Q000276:immunology*; D055815:Young Adult
chemical_list: D022541:Streptococcal Vaccines