EFFICACY OF HEAT-INACTIVATED HEPATITIS B VACCINE IN HAEMODIALYSIS PATIENTS AND STAFF: Double-blind Placebo-controlled Trial

The efficacy of a heat-inactivated hepatitis B vaccine, 3 μg of surface antigen (HBsAg), given at 0, 1, 2, and 5 months, was evaluated in 401 haemodialysis patients in 18 centres by a placebo-controlled, double-blind, randomised trial. The attack-rate of hepatitis B virus (HBV) infections in the control group was 18% over 435 days. The protective efficacy rate of the vaccine was 78% against all HBV infections in the entire study (p= 0·00016), and 94% against HBsAg-positive hepatitis more than 3 months after day 0. Those patients in whom HBV developed showed no evidence of vaccine-acquired anti-HBs. Among 152 similarly randomised staff members receiving three monthly injections, all 5 HBsAg-positive infections occurred in the placebo group (p=0·022). The vaccine induced anti-HBs in 88% of the patients and 100% of the staff. Immediately after the fourth injection, anti-HBs levels were as high in responding patients as in staff. There were no serious side effects. In the four-dose schedule the vaccine provides dialysis patients with protection of the same order as that given by other hepatitis B vaccines to normal subjects.