Evaluation of Efficacy and Tolerability of Hizentra®

This trial will evaluate subjects with Primary Immunodeficiency Disorder (PIDD) who are currently self-infusing Vivaglobin therapy for at least six months prior to changing to Hizentra® therapy. Following screening and enrollment, subjects will continue to self-infuse Vivaglobin® for seven infusions and then be converted to subcutaneous Hizentra® treatment which they will continue for the next 6 months. The study will determine if Hizentra® provides improved subject satisfaction by Treatment Satisfaction Questionnaire for Medication. Diaries related to the local site reactions, the number of infusion sites per subject/per dose, volume of Hizentra® per site, duration of infusions, systemic side effects of the new medication and dose on IgG levels and antibody titers, and local site reactions with Hizentra®.