The change of anti-HBs titer after hepatitis B vaccination in newborn according to dosage and time

ABSTRACT

We studied anti-HBs titer, positive and effective rate in relation to dosages(5microgram, 10microgram) and time interval after third vaccination in 23 infants born to HBsAg negative mother. The babies were divided into two groups. In one group(n=12), 5microgram of Hepavax was administered intramusculary at 1 month, 2 months and 6 months of age, in other group (n=11), 10microgram of Hepavax at same time interval. And the anti-HBs was studied at 2 months and 3 year after third vaccination by radioimmunoassay. The results were as follows 1) The anti-HBs positive rate was 100% in two groups at 2 months and 3 years after vaccination. 2) The geometric mean anti-HBs titer at 2 months after third vacciantion was 9418.3+/-13041.5 IU/L in 5microgram group and 12750.0+/-12750.5 IU/L in 10microgram group, and 3 year after vaccination, 949.4+/-1404.0 IU/L in 5microgram group, 1067.4+/-1067.7 IU/L in 10microgram group. There were no significant difference between two groups, although mean anti-HBs titer decreased significantly after 3 years. 3) The effective rate at 3 years after vaccination was 66.7% in 5 microgram group and 72.8% in 10microgram group. There was no statistical significant difference between two groups.