Non immune patients (anti-HBs <10 IU/L) and patients with unknown immunity were eligible for nurse intervention, consisting of (1) documenting HBV serostatus in patients with previously missing information, (2) providing vaccination (3 doses with a minimal interval of 1 and 6 months) to non-immune patients, (3) measuring vaccination effectiveness 1 month after the 3rd dose and (4) providing a second course of vaccination to non-responders.