1987 Volume 61 Issue 7 Pages 810-818
A long-term follow-up study was carried out after the injection of HB vaccine for children. Positive rate for anti-HBs showed 83.3% in the first year but decreased to 60.0% in the second year. Prevalence of high responder (Cut off index (C. I.) over 50) also decreased from 43.5% after 9 months to 21.7% after 2 years. Seronegative rate for anti-HBs in the second and third year were 30.3%(10 of 33) and 16.7%(1 of 6) respectively. These eleven seronegative cases had a low C.I. below 50 and particularly in 7 cases, C.I. was lower than 10.
During the period of observation, there were 8 no and 8 low responders for vaccination, 3 cases with inapparent HBV infection; one from no responders and the remainders from non-vaccine group, and also a case with the elavation of anti-HBs alone probably due to the booster effect.
These findings suggested the necessity of re-vaccination for no responders and the possibility of prevention against HBV infection for low responders.
