Safety and Immunogenicity of a Pentavalent Vaccine Compared With Separate Administration of Licensed Equivalent Vaccines in US Infants and Toddlers and Persistence of Antibodies Before a Preschool Booster Dose: A Randomized, Clinical Trial

Our goal was to compare the safety and immunogenicity of a combination vaccine (DTaP(5)-IPV-Hib; Pentacel) with that of its separately administered, US-licensed equivalent vaccines (diphtheria, tetanus, 5-component acellular pertussis vaccine [DTaP(5); 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) DTaP(5) dose. In this randomized, multicenter study, 1939 healthy infants were immunized at 2, 4, and 6 months of age with 1 of 3 lots of DTaP(5) coadministered with IPV and Hib vaccines or 1 lot of DTaP(5)-IPV-Hib combination vaccine. Subsequently, 849 of these study participants were given a fourth dose of DTaP(5) and Hib vaccines or a fourth dose of DTaP(5)-IPV-Hib at 1 to 16 months of age. Safety was monitored throughout the study, and blood specimens were obtained to assess antibody responses. DTaP(5)-IPV-Hib elicited similar or fewer solicited injection-site and systemic reactions as compared with the separate administration of US-licensed DTaP(5), IPV, and Hib vaccines. Seroresponse and seroprotection rates elicited by DTaP(5)-IPV-Hib were noninferior to US-licensed equivalent vaccines after the infant series and after the fourth dose. Children immunized with DTaP(5)-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 DTaP(5)-IPV-Hib and separate-vaccine groups. Persistence of antibodies to the fifth (preschool) dose was also similar between groups. DTaP(5)-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 DTaP(5)-IPV-Hib versus the separately administered, US-licensed equivalent vaccines. DTaP(5)-IPV-Hib is a suitable replacement for separately administered DTaP, IPV, and Hib vaccines.