Immunogenicity and safety of a tetravalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus vaccine

The objective of this study was to investigate whether a tetravalent vaccin e containing diphtheria, tetanus, monocomponent acellular pertussis and ina ctivated poliovirus (DTaP-IPV) was immunogenic and safe compared with the v accination regime used in Denmark at the time of the study, The study mas p erformed as an open controlled study in which 270 Danish children were enro lled at their 5 weeks' routine examination. The children were allocated to receive either (i) DTaP-IPV (12.5 Lf, 7 Lf, 40 mu g, 40, 8, 32 DU) at 3, 5 and 12 months of age (n = 186) or (ii) DT-IPV (50 Lf, 12.5 Lf, 40, 8, 32 DU ) at 5, 6 and 15 months of age plus whole-cell pertussis vaccine (greater t han or equal to 4 IU) at 5 and 9 weeks and at 10 months of age (n = 84), No hypotonic hyporesponsive episodes or other vaccine-related serious adverse events were seen. Local reactions, febrile and crying episodes with the in vestigational vaccine (DTaP-IPV) were similar to the reactions seen with th e existing DT-IPV vaccine, One month after completing the vaccination sched ule, all children had antibodies above the defined protective antibody conc entrations to polio, tetanus and diphtheria. For pertussis toxin, there was a significantly better response in the investigational vaccine group, We t herefore conclude that, when used according to the schedule tested, the tet ravalent DTaP-IPV vaccine is safe and immunogenic, In addition, the number of visits and the number of injections necessary are reduced with this vacc ine and vaccination schedule.