A randomized phase IV study of the liquid pentavalent combination vaccine to evaluate the safety, immunogenicity (short term and long term) and clinical consistency of three production lots of the vaccine.

Inclusion Criteria:

• Healthy children in the age group six to eight weeks
• Born after a normal gestational period (36 - 42 weeks)
• Mother's HBsAg (hepatitis B surface antigen) assured negative.
• Father, mother or legally acceptable representative properly informed about the study and having signed the informed consent form.

Exclusion Criteria:

• Administration of immunoglobulin or any blood products since birth.
• Use of any investigational, un-registered drug, or vaccine other than the study vaccine (with the exception of oral polio vaccination OPV & BCG vaccine) during the study period or within 30 days preceding the first dose of the study vaccine.
• Previous vaccination or evidence of infection with DTP or Hib.
• History of allergic disease or reaction likely to be exacerbated by any component of the vaccine including allergy to antibiotics.
• Major congenital or hereditary immunodeficiency.
• Infants born to mothers known to be HIV positive.
• Infants having evidence of disease or fever, history of allergic disease or persistent hematological, hepatic, renal, cardiac or respiratory disease and signs of a CNS disorder at the time of vaccination.
• Infants showing any of the following reactions after any dose of study vaccine will be withdrawn for subsequent doses: body temperature more than 40.40C, persistent screaming or crying for 3 hours within 48 hours of vaccination, seizures, encephalopathy and hypersensitivity reaction.
• Parent/s or guardian of subject unable to maintain diary card