Safety and immunogenicity of acellular diphtheria-tetanus-pertussis and Haemophilus conjugate vaccines given in combination or at separate injection sites.

This prospective, double-blind, randomized trial compared the immunogenicity and reactogenicity of acellular diphtheria-tetanus-pertussis vaccine and Haemophilus influenzae type b conjugate vaccine-diphtheria toxoid conjugate, given at separate injection sites or at a single site, in 79 children 18 months of age who had received three prior immunizing doses of whole-cell diphtheria-tetanus-pertussis vaccine. No significant differences were observed.