Clinical development of a combined diphtheria, tetanus, acellular pertussis, and hepatitis B vaccine in Italy.

In Italy, oral polio vaccine and diphtheria and tetanus (DT) and hepatitis B (HB) vaccinations are required by law. At present, infants receive DT and HB by two separate intramuscular injections during one visit, and most receive an additional injection of acellular pertussis vaccine at the same time. Although simultaneous administration of the vaccines has the advantage of only one medical visit, it is time-consuming for staff, very expensive, painful to the infants, and stressful for parents. A much better solution would be to administer a ready-to-use mixture containing all the vaccines, provided that this combination vaccine had good local and systemic safety profiles and clinical and immunologic efficacy. To evaluate such a combination vaccine in healthy infants at 3, 5, and 11 and at 2, 4, and 6 months of age, a multicenter clinical study is underway in Italy.