INTERACTION OF HAEMOPHILUS-INFLUENZAE TYPE-B CONJUGATE VACCINES WITH DIPHTHERIA-TETANUS-PERTUSSIS VACCINE IN CONTROL TESTS

The effects of combining three Haemophilus influenzae type b (Hib) cap sular polysaccharide vaccines, conjugated to different proteins, with DTP vaccine on the subsequent control testing were examined. The addit ion of the Hib vaccines had little effect on the reactogenicity or the potency of the whole-cell pertussis component. The potency of, and an tibody responses to, the diphtheria component,were also unaffected in all three combinations. However, combination with the Hib vaccine comp rising polysaccharide conjugated to tetanus toroid resulted in a five fold potentiation of the tetanus potency and large increases in the an tibody responses to tetanus toxin and toroid and Hib polysaccharide. T hese results have implications for. the control testing of combined va ccines containing a whole-cell pertussis component and Hib polysacchar ide-tetanus protein conjugate vaccine.