SAFETY AND IMMUNOGENICITY OF A 3 DOSE COURSE OF COMVAXTM IN HEALTHY TAIWANESE INFANTS 

Lee PI, Lee CY, Tsai P*, Poerschke G*, Ma-Choy H*, Hesley TM*

Dept. of Pediatrics, National University Hospital, Taipei, Taiwan; MSD Taiwan*, MSD Asia Ltd.*, Merck & Co., Inc., PA, USA* 

 

Objective: To assess the safety and immunogenicity of COMVAXTM, a bivalent Haemophilus influenzae type b (Hib)-hepatitis B (HB) vaccine using a standard Taiwanese vaccination schedule, aiming to improve convenience and compliance.

Design: Healthy infants, who received recombinant HB vaccine and Bacille Calmette-Guérin vaccine at birth, were enrolled.  COMVAXTM was administered at 6, 14 and 52 weeks of age. Diptheria-tetanus-whole cell pertussis and oral polio vaccines were given at 6, 14 and 22 weeks.  Blood samples were collected at 6, 22 and 56 weeks. Adverse Events [AEs] were monitored for 15 days after each vaccination visit. Merck Research Laboratories (USA) measured anti-PRP (Farr-type RIA) and anti-HBs (AUSABÒ RIA; Abbott Laboratories, North Chicago, IL).

Results: 151 infants were enrolled; 5 were lost to follow-up. AEs following COMVAXTM injection were generally mild and transient. 4 serious AEs, judged unrelated to vaccination, were reported. No-one discontinued due to an AE. Anti-PRP results: At 6 weeks, 27.7% (41/148) >0.15 μg/ml, 6.1% (9/148) >1.0μg/ml (GMC=0.1); At 22 weeks, 98% (144/147) >0.15 μg/ml, 82.3% (121/147) >1.0μg/ml (GMC=3.9); At 56 weeks, 99.3 % (145/146) >0.15 μg/ml, 98.6 % (144/146) >1.0 μg/ml (GMC=14.0). Anti-HBs results: At 6 weeks, 56% (84/150) had ³10 mIU/ml (GMC=9.9); At 22 weeks, 93.2 % (137/147) ³10 mIU/ml (GMC=125.3); At 56 weeks, 97.9 % (143/146) ³10 mIU/ml (GMC=1509.3).

Conclusion: A 3-dose course of COMVAXTM at 6, 14, and 52 weeks of age is well-tolerated and induces robust immune responses against Hib and HB infections. In Asia, such a schedule offers flexibility in incorporating Hib vaccine into EPI programs.

 

 
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