[Clinical trial of inactivated hepatitis A vaccine]

A clinical trial was carried out for a lypophilized inactivated hepatitis A vaccine in order to confirm its safety and antibody response. The vaccine used for the study has been developed by Denka Institute of Biological Science (Lot. D-01), Chiba Serum Institute (Lot. C-01) and The Chemo-Sero-Therapeutic Research Institute (Lot. K-02). Thirty-six volunteers were selected and employed for the present study from healthy male adults carrying no antibody against hepatitis A virus (HAV). They were divided into three dose groups; 1.0 microgram, 0.5 microgram and 0.25 microgram viral protein respectively. Each groups were injected intramuscularly 3 times with 0, 1 and 6 months interval. As the results, though, slight side effects such as local pain were found in 16 cases out of 99 total injected, but no abnormal value was observed in the blood and urine examinations. On the other hand, the mean values of serum anti-HAV at 2 months after the first injection in 1.0 microgram, 0.5 microgram and 0.25 microgram dose-groups were 562 mIU/ml, 323 mIU/ml and 134 mIU/ml, respectively, and at the 7 months, 3630 mIU/ml, 1288 mIU/ml and 1000 mIU/ml, respectively. Namely, the high immunogenicity and safety of the vaccine were confirmed in this trail.