Objective: To obtain immunogenicity and safety data for a pentavalent combination vaccine (diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Hib polysaccharide-conjugate).
Design: Multicenter, open, Phase III clinical study. A DTaP-IPV//PRP approximately T vaccine (Pentaxim) was given at 6,10,14 weeks of age; and Hepatitis B vaccine at 0,6,14 or at 6,10,14 weeks of age. Immunogenicity assessed 1 month post-3rd dose; safety assessed for 30 minutes by the investigator, then by parents and investigators to 8 days and 30 days post-vaccination.
Setting: Tertiary-care hospitals.
Participants/patients: 226 healthy Indian infants (6 weeks of age).
Main outcome measures: Immunogenicity and safety.
Results: Immunogenicity was high for each vaccine antigen, and similar to a historical control study (France) following a 2,3,4 month of age administration schedule. Post-3rd dose, 98.6% of subjects had anti-PRP >0.15 mg/mL and 90.0% had titers >1.0 mg/mL; the anti-PRP GMT was 4.1 micrograms/mL. Seroprotection rates for diphtheria and tetanus (>0.01 IU/mL) were 99.1% and 100%; and 100%, 99.1% and 100%, for polio types 1,2 and 3 (>8 [1/dil]) respectively. Anti-polio GMTs were 440.5,458.9, and 1510.7 (1/dil) for types 1,2 and 3 respectively. The vaccine response rates to pertussis antigens (4-fold increase in antibody concentration) were 93.7% for PT and 85.7% for FHA; the 2-fold increase was 97.1% and 92.4%. Vaccine reactogenicity was low with adverse reaction incidence not increasing with subsequent doses.
Conclusion: The DTaP-IPV//PRP approximately T vaccine, given concomitantly with monovalent hepatitis B vaccine, was highly immunogenic at 6, 10 and 14 weeks of age in infants in India. The vaccine was well tolerated.