COMPLIANCE WITH IMMUNIZATION AGAINST HEPATITIS-B - A PRAGMATIC STUDY IN SEXUALLY-TRANSMITTED DISEASE CLINICS

The efficacy of a vaccine is based primarily on the adherence of the s ubject to the immunization schedule. This paper compares the complianc e rates (CR) for the third dose of hepatitis B virus (HBV) vaccine giv en according to one of two vaccination schedules among subjects attend ing two sexually transmitted disease (STD) clinics, and the potential influence of place of vaccine administration (STD clinic or at a vacci nation centre). Heterosexual, anti-HBc seronegative subjects (n = 331) were randomized to a 0-1-6 month (n = 161) or a 0-1-2-12 month schedu le (n = 170) in this prospective, randomized, parallel pragmatic study . Some subjects (n = 50) attended and were vaccinated at one STD clini c (centre A), whereas 281 attended another clinic (centre B) but were referred to a vaccination centre for administration of vaccine. About 31% (103/331) of the subjects received at least three vaccine doses. O n assessing the CR at the 3rd dose in all randomized subjects, we obse rved 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 no t affected by the schedule. On the other hand, the 0-1-2-12 schedule w as associated with a significantly better CR (p = 0.02) at the 3rd dos e than the 0-1-6 month schedule among subjects who comply with the fir st two doses; the actual site of vaccine administration (in situ (A) v ersus referred (B)) does not affect the CR. On assessing the CR for th e booster dose (month 12) in the 0-1-2-12 schedule, eve observed that the CR is significantly better (p < 0.001) if the vaccine is administe r ed at the STD attending clinic (A) in all randomized subjects and am ong those who comply with the first three doses. We conclude that the CR could be increased by vaccinating all subjects at the STD clinic. A mong 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 schedu le. However, the need for administration of a booster dose (month 12) in the former schedule does not allow us to recommend this in preferen ce to the latter.