Program Schedule

1335
Transfer and Persistence of Antibodies in Infants Following Maternal Immunization with an Investigational Trivalent Group B Streptococcus Vaccine

Session: Oral Abstract Session: Clinical Trials
Saturday, October 11, 2014: 11:30 AM
Room: The Pennsylvania Convention Center: 109-AB
Background:

Group B Streptococcus (GBS) is a serious cause of meningitis and sepsis in young infants. We assessed maternal immunization with an investigational trivalent GBS polysaccharide-CRM conjugate vaccine, with follow-up of both mothers and infants (clinicaltrials.gov NCT01446289).

Methods: In a phase II, observer-blind, placebo-controlled study, 86 pregnant women were enrolled at 24–35 weeks gestation and randomized 3:2 to receive intramuscular placebo (saline) or trivalent GBS vaccine containing 5 µg of glycoconjugates of each of GBS serotypes Ia, Ib and III. GBS serotype-specific antibodies were measured in mothers pre- and Day 31 post-immunization, and in mothers and infants at delivery and Day 91 post-partum. Safety was assessed up to at least 5 months postpartum.

Results:

Of 86 pregnant women enrolled (age 29.8 ± 5.1 years, mean ± SD), 51 received vaccine and 35 placebo at 30.0 ± 3.3 weeks gestation. Low pre-immunization antibodies against serotypes Ia, Ib and III increased 16-, 23- and 20-fold, respectively, at delivery. Among maternal-infant pairs with detectable antibodies, placental transfer was 81% (n=38), 70% (n=35) and 65% (n=33), against serotypes Ia, Ib and III. Infants of vaccinated mothers had increased antibody levels at birth which persisted above placebo group levels through day 91 of age.

 

ELISA GMCs (µg/mL) [95% CI]

GBS Serotype

Ia

Ib

III

Study Group

GBS

Placebo

GBS

Placebo

GBS

Placebo

Mothers

N

51

35

51

35

51

35

GMC - Delivery

[95% CI]

5.22

[3.37, 8.1]

0.37

[0.22, 0.63]

2.41

[1.48, 3.94]

0.13

[0.07, 0.23]

1.90

[1.15, 3.12]

0.11

[0.06, 0.19]

Infants

N

35

25

31

20

30

22

GMC - Birth

[95% CI]

5.14

[2.64, 10]

0.33

[0.15, 0.71]

2.93

[1.14, 7.57]

0.1

[0.03, 0.32]

1.93

[0.82, 4.59]

0.07

[0.02, 0.18]

Infants

N

35

25

35

25

35

25

GMC - 91 days

[95% CI]

1.28

[0.76, 2.16]

0.25

[0.13, 0.46]

0.54

[0.25, 1.19]

0.06

[0.03, 0.16]

0.43

[0.21, 0.86]

0.07

[0.03, 0.15]

Mild or moderate solicited reactions were reported in 54% and 53% of vaccine and placebo groups, respectively, with no vaccine-related SAEs reported.

Conclusion: One dose of trivalent GBS vaccine was well-tolerated with no concerning safety signals in pregnant women, and induced increased antibody concentrations in mothers and their infants.

Scott A Halperin1, Gilbert Donders2,3,4, Roland Devlieger5, Sherryl Baker6, Pietro Forte6, Frederick Wittke6, Karen Slobod, MD6 and Peter M Dull, MD6, (1)Dalhousie University, Canadian Center for Vaccinology, Halifax, NS, Canada, (2)Femicare Clinical Research for Women, Tienen, Belgium, (3)Dept Obstetrics and Gynaecology, Regional Hospital H Hart, Tienen, Belgium, (4)University Hospital Antwerpen, Antwerp, Belgium, (5)Dept Obstetrics and Gynaecology, University Hospital Gasthuisberg, Leuven, Belgium, (6)Novartis Vaccines and Diagnostics,Inc., Cambridge, MA

Disclosures:

S. A Halperin, Novartis Vaccines : Investigator, Consulting fee

G. Donders, Novartis Vaccines : Investigator, Consulting fee

R. Devlieger, Novartis Vaccines : Investigator, Consulting fee

S. Baker, Novartis Vaccines : Employee, Salary

P. Forte, Novartis Vaccines : Employee, Salary

F. Wittke, Novartis Vaccines : Employee, Salary

K. Slobod, Novartis Vaccines : Employee, Salary

P. M Dull, Novartis Vaccines: Employee, Salary

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