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.