STRICTLY respiratory human disease. It is one of the most common vaccine-preventable CHILDHOOD diseases.Diphtheria and tetanus toxoids have been combined with pertussis antigens and used as a combination DTP vaccine since the 1940s. More recently, this DTP combination has been used as the basis for the development of combination vaccines containing additional vaccine antigens added singly or in additional combinations such as Haemophilus influenza type b, hepatitis B, and inactivated poliovirus, allowing multiple vaccine antigens to be DELIVERED via a single injection.In addition, in some DTP vaccines, the diphtheria dose has been reduced and pertussis antigen has been modified to ALLOW these vaccines to be used for booster doses in adolescents and adults. Because these toxoids and antigens are now frequently used as combined vaccines, most adverse events following immunization reported in these vaccines are likely due to the safety profile of their individual components.Diphtheria toxoid is prepared by formalin inactivation of diphtheria toxin. Usually, it is available as a preparation adsorbed with aluminum hydroxide or phosphate and combined with other toxoids or vaccine antigens. The potency of the diphtheria vaccine used for the immunization of children should not be less than 30 IU per single human dose, while for adults; the potency is about a third of the dose for children. Monovalent single antigen diphtheria toxoid is currently commercially unavailable.Tetanus toxoid is a preparation of formalin-inactivated toxin. The toxoid is availably adsorbed with aluminum phosphate or hydroxide, alone or in combination with other toxoids or vaccines.The potency of tetanus toxoid, expressed in International Units, varies widely according to the preparation and the manufacturer, but WHO stipulates the potency of tetanus vaccine used for the immunization of children should not be less than 40 IU per single human dose. The minimum potency specification for tetanus vaccine intended for booster immunization of older children and adults may be LOWER and should be approved by the National Regulatory Authority (NRA). Single antigen adsorbed tetanus toxoid is available with a toxoid content of 2 to 10 Lf/dose.