SINGLE-DOSE HEPATITIS-A VACCINATION - COMPARISON OF DIFFERENT DOSE LEVELS IN ADOLESCENTS

The effect of two dose levels of inactivated hepatitis A vaccine was i nvestigated for immunogenicity and reactogenicity in an open study in adolescents. The subjects were randomized into two groups and to recei ve a priming nose of 720 EL. U or 1440 EL. U of hepatitis A antigen, r espectively. A booster of the same dose level was given at month 6. In group I, receiving 720 EL. U, the seroconversion rates at 15 days and 1 month were 92% and 99%. The corresponding rates for group 2, receiv ing 1440 EL. U, were 98% and 100%. Higher geometric mean titles of ant ibody to hepatitis A virus were noted at 1, 6 and 7 months in the grou p receiving 1440 EL. U. The vaccine was well tolerated in both groups. The most frequent side effect was transient soreness at the site of i noculation. No serious adverse reactions were observed. The study demo nstrated that inactivated hepatitis A vaccine is safe and immunogenic at a dose level of 720 EL. U or 1440 EL. U in adolescents. Copyright ( C) 1996 Elsevier Science Ltd.