This paper presents the results of four separate phase III trials, which assessed the immunogenicity and reactogenicity of DTPw-HBV/Hib 2.5 in comparison with licensed Tritanrix(TM)-Hep B (GlaxoSmithKline Biologicals) and Hiberix(TM) (10 mu g PRP), given as separate or mixed injections (3 trials) or with or without hepatitis B vaccine at birth (1 trial). The inummogenicity of DTPw-HBV/Hib 2.5 was non-inferior to the reference vaccine regimen in terms of seropositivity rates. The overall reactogenicity profile of DTPw-HBV/Hib 2.5 was also similar to that of the reference vaccine regimen. These results confirm the previously established immunogenicity and safety of reduced dose PRP conjugated vaccine regimens. (c) 2007 Published by Elsevier Ltd.