OBJECTIVE. Our goal was to compare the safety and immunogenicity of a combination vaccine (DTaP5-IPV-Hib; Pentacel) with that of its separately administered, US-licensed equivalent vaccines (diphtheria, tetanus, 5-component acellular pertussis vaccine [DTaP5; Daptacel], inactivated poliovirus vaccine [IPV; IPOL], and Haemophilus influenzae type b [Hib] vaccine [ActHIB]), when administered to infants and toddlers concomitantly with other routinely recommended vaccines and to assess antibody persistence from the fourth dose in toddlers to the fifth (preschool) DTaP5 dose.
SUBJECTS AND METHODS. In this randomized, multicenter study, 1939 healthy infants were immunized at 2, 4, and 6 months of age with 1 of 3 lots of DTaP5 coadministered with IPV and Hib vaccines or 1 lot of DTaP5-IPV-Hib combination vaccine. Subsequently, 849 of these study participants were given a fourth dose of DTaP5 and Hib vaccines or a fourth dose of DTaP5-IPV-Hib at 1 to 16 months of age. Safety was monitored throughout the study, and blood specimens were obtained to assess antibody responses.
RESULTS. DTaP5-IPV-Hib elicited similar or fewer solicited injection-site and systemic reactions as compared with the separate administration of US-licensed DTaP5, IPV, and Hib vaccines. Seroresponse and seroprotection rates elicited by DTaP5-IPV-Hib were noninferior to US-licensed equivalent vaccines after the infant series and after the fourth dose. Children immunized with DTaP5-IPV-Hib had higher antibody geometric mean concentrations to pertussis toxoid and filamentous hemagglutinin; children immunized with the separate vaccines had higher responses to pertactin. Hib antibody responses to Hib polysaccharide were nearly identical in the DTaP5-IPV-Hib and separate-vaccine groups. Persistence of antibodies to the fifth (preschool) dose was also similar between groups.
CONCLUSIONS. DTaP5-IPV-Hib combination vaccine was shown to be immunogenic and well tolerated. No clinically important differences in the safety or immunologic profiles were noted for DTaP5-IPV-Hib versus the separately administered, US-licensed equivalent vaccines. DTaP5-IPV-Hib is a suitable replacement for separately administered DTaP, IPV, and Hib vaccines.