An immunogenic composition comprising of Diphtheria toxoid antigen (D), tetanus toxoid (T) antigen, Hepatitis B surface antigen (HBsAg), inactivated whole-cell B. pertussis (wP) antigen, Haemophilus influenzae type B (Hib) capsular saccharide conjugated to a carrier protein, Inactivated Polio Virus (IPV) antigen and additionally one or more antigens and the method of preparing the same. A fully liquid combination vaccine, showing improved immunogenicity, reduced reactogenicity and improved stability. Improved methods of formaldehyde inactivation, improved adsorption profile of Diphtheria toxoid antigen (D), tetanus toxoid (T) antigen and Hepatitis B (HepB) surface antigen adsorbed individually onto aluminium phosphate adjuvant, minimum total aluminum content (Al3+) and optimized concentration of 2-phenoxyethanol (2-PE) as preservative.
