Immune response to hepatitis B vaccine in drug addicts

Drug addicts are at high risk of hepatitis B infection and are therefore candidates for vaccination against hepatitis B. Since drug addicts may have an impaired immune response, and low compliance for therapy extending over several months, we evaluated a vaccination scheme according to the instruction of the manufacturer (HB- Vax 20 micrograms at zero, one and six months) in drug addicts using daily methadone (Group M), in drug addicts in residential detoxification programmes (Group D), and in treatment centre staff who were seronegative for hepatitis Bs (Group S). All 23 controls and 20 of 21 of Group D completed the vaccination programme, in contrast to 14 of 24 in Group M. Anti-HBs developed in 91 per cent of Group S and in all addicts tested at six months. Anti-HBs titres at seven months were higher than 100 RIA units in 55 per cent of Group S, in 94 per cent of Group D and in 44 per cent of Group M. We conclude that HB- Vax induces production of anti-HBs equally well in drug addicts and in controls: a shorter-duration vaccination schedule might be more appropriate for 'non-captive' drug addicts living outside therapeutic communities.