[Safety and immunogenicity of a new inactivated hepatitis A vaccine].

BACKGROUND: To evaluate the safety and immunogenicity of a new inactivated hepatitis A virus (HAV) vaccine. METHODS: In a randomized controlled trail thirty-one HAV-seronegative adults were enrolled and randomly assigned to either study group or control group. Subjects in the study group were given 1000 units of the new inactivated HAV vaccine, with a booster at 3 months. Subjects in the control group were given 720 ELISA units Havrix, produced by SmithKline Beecham Biologicals, with a subsequent dose at 3 months. Local and systematic reactions and serum response to the vaccines were compared between the two groups. RESULTS: Mild local reactions were noted in one subject from the study group and two from the control group after primary vaccination. Mild systematic reactions were reported in two subjects from each group after primary vaccination and in one subject from the study group after booster vaccination. Seroconversion rates were 94%, 100%, and 100% in the study group at 1, 3, and 4 (1 month after booster) month, respectively. The corresponding figures were 73%, 80% and 100% in the control group. Geometric mean antibody titers were 139.2 mIU/ml, 137.7 mIU/ml, and 1 066.7 mIU/ml at 1, 3, and 4 months,respectively, in the study group,and 104.3 mIU/ml, 111.3 mIU/ml, and 760.7 mIU/ml in the control group. CONCLUSIONS: The new inactivated hepatitis A vaccine was safe and highly immunogenic.