Comparative study of the reactogenicity of a three-component acellular pertussis vaccine and whole-cell pertussis vaccine administered to healthy Singaporean infants.

The objective of this study was to assess and compare the reactogenicity of GlaxoSmithKline (GSK) Biologicals' diphtheria-tetanus-tricomponent acellular pertussis vaccine (DTPa) and the locally used combined diphtheria-tetanus-whole-cell pertussis vaccine (DTPw) as a primary vaccination course in healthy infants at the age of 3, 4 and 5 months. A phase IV, single-blinded, randomized comparative clinical study involved one hundred and eighty healthy infants with two study groups in a 2:1 ratio to receive either DTPa or DTPw vaccine which were administered intramuscularly at the right anterior-lateral aspect of the thigh. The incidence and intensity of local solicited symptoms such as pain, redness and swelling at injection site and general solicited symptoms such as fever and fussiness were evaluated. Serious adverse events were followed for one month after each vaccination. The overall incidence of local and general symptoms was significantly higher in the group receiving locally used DTPw vaccine as compared to the group receiving GSK DTPa vaccine. Solicited local symptoms, pain (47.4% vs 15.1%), redness (95.9% vs 84.9%) and swelling (46.2% vs 18.5%), were reported more frequently in the group receiving DTPw vaccine than in the group receiving DTPa vaccine. Fever (> or = 37.5 degrees C) (52% vs 14.6%) and fussiness (60.8% vs 33.6%) were also more commonly reported in the DTPw group. There were six serious adverse events reported (4 with DTPw and 2 with DTPa). None of them related to the study vaccines, as considered by the investigators. Thus it was found that GSK Biologicals' DTPa vaccine was significantly less reactogenic as compared to the locally used DTPw vaccine manufactured by Commonwealth Serum Laboratories when administered as a 3-dose primary vaccination course to healthy infants at the age of 3, 4 and 5 months in Singapore.