@article {Scheifele1105, author = {D. Scheifele and L. Barreto and W. Meekison and R. Guasparini and B. Friesen}, title = {Can Haemophilus influenzae type b-tetanus toxoid conjugate vaccine be combined with diphtheria toxoid-pertussis vaccine-tetanus toxoid?}, volume = {149}, number = {8}, pages = {1105--1112}, year = {1993}, publisher = {CMAJ}, abstract = {OBJECTIVE: To assess the side effects and immune responses after three serial doses of PRP-T vaccine (a Haemophilus influenzae type b [Hib]-tetanus toxoid conjugate vaccine) given concurrently or mixed with adsorbed DPT vaccine (diphtheria toxoid-pertussis vaccine-tetanus toxoid). DESIGN: Multicentre randomized controlled trial. SETTING: Four public health units in western Canada. PARTICIPANTS: Healthy infants 8 to 15 weeks old at entry who were able to receive routine primary vaccinations. Of 444 infants enrolled, 433 (98\%) completed the study. INTERVENTIONS: All infants received PRP-T and DPT vaccines at 2, 4 and 6 months of age: half received them mixed in one injection and the others as separate, bilateral injections. MAIN OUTCOME MEASURES: Side-effects 24 and 48 hours after each dose and serologic responses to each vaccine component. RESULTS: Follow-up was obtained after all 1312 vaccinations. Fever was infrequent in the two treatment groups. Local adverse effects of the PRP-T vaccine were infrequent and mild (e.g., redness was noted in 5.9\% of cases and the area of redness was more than 2.5 cm in diameter in 0.8\%). The incidence rate of local effects of the DPT-containing vaccines was the same in the two groups except for tenderness, which was more frequent in the group given the mixed vaccine (26.6\% v. 17.9\%, p \< 0.001). Serologic data were available for 97\% of the subjects. After the three doses 98.1\% of the subjects had a PRP antibody level of 0.15 micrograms/mL or more, and 87.9\% had a level of 1.0 micrograms/mL or more, both levels compatible with protection against Hib. Responses to PRP-T were comparable between the treatment groups as were responses to the diphtheria and tetanus toxoids. Pertussis agglutinin titres were reduced after administration of one of two PRP-T lots mixed with DPT vaccine, but responses to four other pertussis antigens were not impaired. CONCLUSION: PRP-T vaccine is well tolerated and immunogenic. Combined PRP-T and DPT vaccines performed satisfactorily and may be the preferred method of administration.}, issn = {0820-3946}, URL = {https://www.cmaj.ca/content/149/8/1105}, eprint = {https://www.cmaj.ca/content}, journal = {CMAJ} }