Compliance with immunization against hepatitis B. A pragmatic study in sexually transmitted disease clinics

Abstract

The efficacy of a vaccine is based primarily on the adherence of the subject to the immunization schedule. This paper compares the compliance rates (CR) for the third dose of hepatitis B virus (HBV) vaccine given according to one of two vaccination schedules among subjects attending two sexually transmitted disease (STD) clinics, and the potential influence of place of vaccine administration (STD clinic or at a vaccination centre). Heterosexual, anti-HBc seronegative subjects (n=331) were randomized to a 0-1-6 month (n=i61) or a 0-1-2-12 month schedule (n=170) in this prospective, randomized, parallel pragmatic study. Some subjects (n=50) attended and were vaccinated at one STD clinic (centre A), whereas 281 attended another clinic (centre B) but were referred to a vaccination centre for administration of vaccine. About 31% (103331) of the subjects received at least three vaccine doses. On assessing the CR at the 3rd dose in all randomized subjects, we observed that administration of the vaccine at the STD clinic attended (A) was associated with a significantly better CR (p<0.01) than that of the subjects referred to a vaccination centre (B), while the CR is not affected by the schedule. On the other hand, the 0-1-2-12 schedule was associated with a significantly better CR (p=0.02) at the 3rd dose than the 0-1-6 month schedule among subjects who comply with the first two doses; the actual site of vaccine administration (in situ (A) versus referred (B)) does not affect the CR. On assessing the CR for the booster dose (month 12) in the 0-1-2-12 schedule, we observed that the CR is significantly better (p<0.001) if the vaccine is administered at the STD attending clinic (A) in all randomized subjects and among those who comply with the first three doses. We conclude that the CR could be increased by vaccinating all subjects at the STD clinic. Among those subjects who comply with the first two doses, the CR at the 3rd dose is better with the 0-1-2 schedule than with the 0-1-6 schedule. However, the need for administration of a booster dose (month 12) in the former schedule does not allow us to recommend this in preference to the latter.