Daclizumab will be administered at a dose of 1 mg/kg peripheral IV given immediately pre-transplant, and at 2, 4, 6, and 8 weeks after transplant, for a total of 5 doses (over 8 weeks). If a subsequent islet infusion is required beyond this induction period, then a further 5 dose course of daclizumab will be given according to the same schedule. If the second (or third) transplant occurs and no daclizumab was given in the preceding 7 days, then the dosing regimen will begin at the time of transplant. If daclizumab has been administered within the past 7 days, then the dose at transplant is omitted, and the first dose given 2 weeks post transplant.