Randomized, Controlled, Multicenter Study of the Immunogenicity and Safety of a Fully Liquid Combination Diphtheria–Tetanus Toxoid–Five-Component Acellular Pertussis (DTaP₅), Inactivated Poliovirus (IPV), and Haemophilus influenzae Type b (Hib) Vaccine Compared with a DTaP₃-IPV/Hib Vaccine Administered at 3, 5, and 12 Months of Age

This study compared the levels of immunogenicity and safety of diphtheria-tetanus toxoid-five-component acellular pertussis (DTaP(5)), inactivated poliovirus (IPV), and Haemophilus influenzae type b (Hib) (DTaP(5)-IPV-Hib) and DTaP(3)-IPV/Hib vaccines for study participants 3, 5, and 12 months of age. Post-dose 3 noninferiority criteria comparing DTaP(5)-IPV-Hib to DTaP(3)-IPV/Hib using rates of seroprotection were demonstrated against diphtheria, tetanus, and polio types 1 to 3, but not for polyribosylribitol phosphate (PRP). While PRP did not meet noninferiority criteria, the seroprotection rate and geometric mean concentration (GMC) were high, indicating a clinically robust immune response. GMCs or titers for other antigens (including pertussis) and the safety profiles were generally similar between groups. Fully liquid DTaP(5)-IPV-Hib can be administered using the 3-, 5-, and 12-month vaccination schedule. (This study has been registered at ClinicalTrials.gov under registration no. NCT00287092.).