文本框: DTPa-based combination vaccines: Protecting against more diseases with fewer injections Schmitt HJ Johannes Gutenberg University, Mainz, Germany Objective: To reduce the number of injections for infant immunization while accommodating the growing number of recommended antigens for pediatric immunization. Methods: Safety, immunogenicity and reactogenicity of several DTPa-based combination vaccines were determined in large clinical trials in infants according to different vaccination schedules. In addition, to assess the impact of the observed lower Hib response on the incidence of invasive Haemophilus influenzae (Hib) disease, two independent surveillance systems (one hospital- and one laboratory-based) were used in Germany. Results: DTPa-based combination vaccines are safe, they induce little reactogenicity and are highly immunogenic when given for primary immunization and as a booster in the second year of life. The somewhat lower anti-Hib-antibody response, compared with separate administration of the Hib vaccine, is of no clinical relevance, especially since the incidence of invasive Hib disease continues to fall, with a mean annual incidence of 1.01 per 100,000 children. The overall effectiveness of these vaccines against invasive Hib disease was high at 97.4% (95% confidence interval [CI]: 96.0%–98.3%) for those who had received at least one dose. In subjects who received the full three-dose schedule, effectiveness was 98.8% (95% CI: 98.1%–99.2%). Further to the approval of a series of intermediate DTPa-based combination vaccines, the European Licensing Authority recently approved hexavalent combinations with D, T, Pa, HBV, IPV and Hib. Conclusion: DTPa-based combination vaccines are safe, induce little reactogenicity, and are highly immunogenic and efficacious.