To evaluate the immunogenicity of the Chinese hamster ovary cell derived HB vaccine (CHB), CHB and yeast derived HB vaccine (YHB) were given to 110 medical students divided into four groups. CHB was given to group A subcutaneously (0.5 ml, 3 times) and to group B intradermally (0.125 ml, 3times). YHB was given to group C (Y company) and to group D (Z company) subcutaneously (0.5 ml, 3 times).
The and-HBs positive rate at 7 months was 85.7% in group A, 95.8% in group B, and 100% in groups C and D. The percentage responding with high anti-HBs concentration (≥100mIU/ml by RIA) at 7 months was 67.9% in group A, 79.2% in group B, 58.3% in group C and 63.3% in group D. Thus, although the and-HBs positive rate was rather low when CHB was given subcutaneously, it was almost the same as YHB when given intradermally. The percentage of high responders to CHB given both subcutaneously and intradermally was high compared to YHB.
These data suggest that CHB has almost the same immunogenicity to the conventional YHB.