 The secondary objective is to investigate the efficacy of Octagam 10 in replacement therapy in PID by monitoring the rate of occurence of serious bacterial infections, the rate of other infections, the trough pre-next-dose levels of total serum IgG and IgG subclasses IgG1, IgG2, IgG3 and IgG4, the trough pre-next-dose levels of selected antigen specific antibodies, the use of antibiotics, the rate of absence from school work, and the number of days in hospital. 