Immunogenicity and safety of a pentavalent acellular pertussis combined vaccine including diphtheria, tetanus, inactivated poliovirus and conjugated Haemophilus Influenzae type b polysaccharide for primary vaccination at 2, 3, 4 or 3, 4, 5 months of age in infants in China.

The aim was to demonstrate the immunogenicity and safety of a DTaP-IPV//PRP-T combined vaccine (Pentaxim(®)) compared to individual vaccines in infants in the People's Republic of China. Infants (N=792) were randomly assigned to receive DTaP-IPV//PRP-T at 2, 3 and 4 months of age (Group A) or 3, 4 and 5 months of age (Group B), or DTaP (Wuhan Institute of Biological Products), PRP-T (Act-Hib(®)) and IPV (Imovax(®) Polio) at 3, 4 and 5 months of age (Group C). Antibody titers were measured pre- and 1 month after the third vaccination; non-inferiority analyses were performed for seroprotection/seroconversion (SP/SC) rates. Safety was assessed 1 month after the primary series. SP/SC rates for the DTaP-IPV//PRP-T vaccine were high and non-inferior to the controls. Reactogenicity was low for each group and no hypotonic hyporesponsive episode or seizure was reported. In conclusion, the DTaP-IPV//PRP-T vaccine was highly immunogenic, non-inferior to the commercially available control vaccines and had a good safety profile for both primary administration schedules.