186. Women Receiving Group B Streptococcus Serotype III Tetanus Toxoid (GBS III-TT) Vaccine Have Reducesd Vaginal and Rectal Acquisition of GBS Type III
Session: Oral Abstract Session: Pediatric and Adult Vaccines
Friday, October 30, 2009: 12:00 AM
Room: 109-AB
Background: GBS colonizes the vagina and/or rectum without symptoms, but can cause invasive infections in neonates and adults. A vaccine could prevent invasive infections directly or indirectly by decreasing colonization at mucosal sites.
Methods: Double-blind randomized trial of GBS III-TT vs. tetanus and diphtheria toxoids (Td) vaccine in sexually active non-pregnant women aged 18-40 from Pittsburgh, PA, Augusta, GA and Houston, TX who were not GBS colonized at screening.. After vaccination, women were evaluated bimonthly for GBS colonization for 18 months. GBS was detected by selective broth cultures in a central laboratory. GBS was serotyped and anti-type III GBS capsular polysaccharide (CPS) IgG was measured in reference laboratories.
Results: Of 667 randomized women (61% white, 32% black and 5% other), 17 had no subsequent follow-up leaving 650 women available for the intent to treat efficacy analysis. The GBS III-TT vaccine was safe and well tolerated. The most frequently reported adverse events were injection site tenderness (87%) and pain (60%). Symptom severity was greater in the Td than the GBS III-TT vaccine group (P=.001). In the primary efficacy analysis of time to first acquisition of vaginal type III GBS, the vaccine efficacy was 35% (95% confidence interval 1-58%, P= .044). The vaccine efficacy for time to first rectal acquisition of GBS III was 43% (95% CI 11-63%, P= .015). The geometric mean concentration of serum IgG to GBS III CPS at two months post-vaccination was 12.6 (95% CI 9.9-15.8) ug/ml in the GBS III-TT vaccine group, and 0.30 (95% CI 0.25-0.35) in the Td vaccine group, p < .0001, with 95% of women in the GBS III-TT vaccine group and < 1% of the women in the Td group responding with a four-fold rise or greater in serum IgG level above pre-vaccination levels. Non-white women had higher post-vaccination GBS III IgG levels than white women (p = .01), and older women also had higher post-vaccination levels than younger women (p = .01).
Conclusion: GBS III-TT vaccine was safe, elicited a robust and sustained specific IgG response and significantly delayed the acquisition of vaginal and rectal GBS III.
Carol Baker, MD1, Vincent Carey, PhD2, Morven Edwards, MD, FIDSA3, Marian Ewell, ScD4, Patricia Ferrieri, MD5, Daron Ferris, MD6, Paul Fine, MD7, Sharon Hillier, PhD8, Dennis Kasper, MD9, Leslie Meyn, BA10, Lawrence Paoletti, MD2 and  S. Hillier,
Johnson & Johnson Role(s): Consultant, Received: Consulting Fee.
Merck Role(s): Consultant, Received: Consulting Fee.
D. Ferris,
Merck Role(s): Consultant, Received: Speaker Honorarium.
P. Fine, None..
P. Ferrieri, None. 
M. Edwards,
Novartis Vaccines Role(s): Consultant, Received: Consulting Fee.
V. Carey, None..
M. Ewell, None..
L. Meyn, None. 
L. Paoletti,
Taylor and Francis Group Role(s): Other, Co-editor of a book, Received: Licensing Agreement or Royalty.
UpToDate, Inc. Role(s): Other, co-author of book chapter, Received: Licensing Agreement or Royalty, Other Financial Benefit.
D. Kasper,
Novartis Vaccines Role(s): Consultant, Received: Consulting Fee.
C. Baker, None., (1)Baylor Coll. of Med., Houston, TX, (2)Harvard Univ., Boston, MA, (3)Pediatrics, Baylor College of Medicine, Houston, TX, (4)Emmes Corp., Rockville, MD, (5)Univ. of Minnesota Hosp. & Clin., Minneapolis, MN, (6)Med. Coll. of Georgia, Augusta, GA, (7)PPFA, Houston, TX, Houston, TX, (8)University of Pittsburgh, Pittsburgh, PA, (9)Channing Laboratory, Boston, MA, (10)Magee Womens Res. Inst., Pittsburgh, PA

Disclosures:

C. Baker, None

V. Carey, None

M. Edwards, None

M. Ewell, None

P. Ferrieri, None

D. Ferris, None

P. Fine, None

S. Hillier, None

D. Kasper, None

L. Meyn, None

L. Paoletti, None