Israel Medical Association Journal

Background: Previous data showed that new recombi­nant hepatitis B virus vaccine, which contains the S-protein component of the HBV surface together with the Pre-S₁ and Pre-S₂, is considerably more immunogenic than a second-generation recombinant I-IBV vaccine.

Objectives:To compare the immunogenicity and safety of a novel recombinant HBV vaccine S1, Pre-S₁ and Pre-S₂ protein components of the hepatitis B surface antigen - Bio­TM

Hep^TM 10 לg dose, to a licensed vaccine containing only the S-protein component - Engerix-B, 20 לg dose.

Methods: A prospective randomized study included 524 adults - 260 in the Bio-Hep group and 264 in the Engerix-B group. Both vaccines were administered in a three-dose regimen given at 0, 1 and 6 months, and adverse events were recorded on a diary card 5 days after each vaccination. lmmunogenicity was tested by measuring anti-hepatitis B surface antibody.

Results: One month after the third injection, 98% of the BioHep^TM subjects were found to be seroprotected vs. 85.1% of the Engerix-B group. In addition, the geometric mean titers were 2,203 mlU/ml and 326 mlU/ml in the Bio-Hep-B and Engerix-B groups respectively. An immunogenic advantage of Bio-Hep-B was suggested by the rapid onset of antibody response - 66.5% were seroconverted one month after the first injection as compared to 19.3% in the Engerix-B group. No unexpected adverse events were observed, and the recorded events were mild in both groups.

Conclusions: BioHepTM, a novel recombinant HBV vaccine containing 5, Pre-S₁ and Pre-S₂ protein components. at a lower dose, is safe and more immunogenic than the conventional HBV vaccine that contains only S protein.

Background: Chickenpox is a highly contagious childhood infection caused by varicella zoster virus, a virus of the herpes family. Although a mild and self-limiting disease in otherwise healthy children, chickenpox can be a complicated and even life-threatening disease in adults, pregnant women and immunosuppressed individuals. Among infants whose mothers had varicella during the first trimester of pregnancy, 2-3% will develop a congenital VZV syndrome that includes a combination of scarring, limb deformation, central nervous system impairment and ocular injury. In 1974, a live attenuated virus vaccine against VZV was developed in Japan and has been thoroughly tested for safety, efficacy and long-term effects. In March 1995 the vaccine was licensed in the U.S. for use in healthy children only.

Objectives: To determine the rate of immunity to VZV in young Israeli adults.

Methods: On the assumption that a randomly picked sample of 18-year-old army recruits in Israel is representative of the general Jewish population, 900 sera samples were taken for 3 years (1985,1988,1992). The sera were analyzed for IgG to VZV with a commercial ELISA kit using microwells coated with VZV antigens.

Results: A total of 98% of the samples tested positive for VZV antibodies. The difference in serologic values between the recruitment years was not statistically significant.

Conclusion: The majority of the Israeli population reaches adulthood already immunized against VZV, with immigrants having slightly lower immunity rates. Nonetheless, a few dozen cases of chickenpox are diagnosed in the IDF annually. These data should be taken into account when a vaccination program is devised. Should such a program be implemented, it would be interesting to repeat the serosurvey for comparison. A shift in the peak occurrence age might necessitate the administration of a booster vaccine at an older age.

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VZV= varicella zoster virus

IDF= Israel Defense Forces