Hepatitis B virus infection in chronic uremia : long-term follow-up of a two-step integrated protocol of vaccination

Active immunization is crucial for eradicating hepatitis B virus infection from dialysis units. A prospective study was performed in 63 consecutive chronic uremic patients, which included the following: (1) the intramuscular (IM) administration of 40 micrograms of a DNA-recombinant vaccine (Engerix-B, Smith Kline & French Laboratories, Milan, Italy) to all chronic uremic patients at 0, 1, 2, and 6 months; (2) the antibody titer determination at the seventh month (chronic uremic patients with a titer > 100 mIU/mL received an IM booster dose of 40 micrograms at 18 months [group A], and those with a titer < 100 mIU/mL received a further IM dose of 40 micrograms at 12 months [group B]); and (3) the intradermal inoculation of 5 micrograms of vaccine every 2 weeks until the protective titer (> or = 10 mIU/mL) was achieved, and then monthly for 6 months, in chronic uremic patients who did not have a protective titer even after 19 months (group C). Thus, 41, 17, and five chronic uremic patients were allocated to groups A, B, and C, respectively. All developed a protective titer: 79.4%, 84.0%, and 87.5% after the fourth, fifth, and sixth IM dose at 7, 13, and 19 months, respectively. Five chronic uremic patients (group C) achieved seroprotection after 3.8 +/- 0.5 (SEM) intradermal inoculations.