SB-3 (Infanrix-DTPa) is one of a new generation of vaccines for immunisation against pertussis (whooping cough), diphtheria and tetanus. It is a 3-component (pertussis toxin, filamentous haemagglutinin and pertactin) chemically inactivated acellular pertussis pertussis-diphtheria-tetanus toxoid (DTaP) vaccine, and it differs from conventional whole-cell pertussis-diphtheria-tetanus toxoid (DTwP) vaccines in that it comprises inactivated purified Bordetella pertussis antigens rather than whole cells of the bacillus. SB-3, like a number of other DTaP vaccines, elicits a similar or more often, a significantly greater immune response than various DTwP vaccines in healthy infants and young children. initial data from comparative studies indicate that SB-3 also remains immunogenic when given in combination with hepatitis B vaccine or concurrently administered with Haemophilus influenzae type b (HbOC) conjugate vaccine. A combination of SB-3 and H. influenzae type b tetanus (PRP-T) conjugate vaccine results in lower anti-PRP antibody response than when both vaccines are administered concurrently. Data from two large, multicentre, German and Italian studies in infants indicate that the protective efficacy of SB-3 against pertussis was significantly better than one DTwP (DTwP-CON) but similar to another one (DTwP-BW) under investigation. Compared with another DTaP vaccine (BIO-3), SB-3 was just as protective. Overall, the data from these 2 studies indicate that primary vaccination with SB-3 provides effective protection against pertussis, even under the stringent conditions of a household contact with typical pertussis. As the other DTaP vaccines, SB-3 is better tolerated than DTwP vaccines, with a significantly lower incidence of common adverse events such as local reactions (swelling, pain and a erythema), irritability, fever, persistent crying and local tenderness. Clinical experience with SB-3 thus far indicates that, like other DTaP vaccines, it is associated with significantly fewer common (non-serious) adverse events than DTwP vaccines. Less clear is whether it has any advantage over DTwP vaccines with respect to protective efficacy or over other DTaP vaccines with respect to tolerability and protective efficacy. Nevertheless, the available data support the use of SB-3 for infant immunisation, as well as providing a suitable basis for the development of new combination vaccines.