Israel Medical Association Journal

Background: Guidelines recommend hepatitis B virus (HBV) vaccination of all adults positive for human immunodeficiency virus (HIV). Immune responses to single-antigen HBV vaccine among HIV-positive patients are low when compared with HIV-negative adults. Sci-B-Vac™ is a recombinant third-generation HBV that may be advantageous in this population.

Objectives: To examine the immune responses to Sci-B-Vac among HIV-positive adults.

Methods: We conducted a prospective cohort study involving HIV-positive adults who had negative HBV serology (HBSAg, HBSAb, HBcoreAb). Sci-B-Vac at 10 µg/dose was administered intramuscularly upon recruitment and after 1 and 6 months. HBSAb levels were checked 1 month after each dose; a level > 10 mlU/ml was considered protective. Data regarding age, gender, CD4 level, and viral load were collected.

Results: The study group comprised 31 patients. Average CD4 count was 503 ± 281 cells/ml, and average viral load was 44 copies/ml. Median interquartile range (IQR) HBVAb titers after the first, second and third immunizations were 0 (0, 3.5), 30 (6, 126) and 253 (81, 408) mlU/ml. Significant titer elevations were found between the second and third immunizations (P = 0.0003). The rate of patients considered protected was 16% after the first, 65% after the second (P < 0.0001), and 84% after the third dose (P = 0.045). No adverse events were reported. More patients under the age of 40 years responded to the first immunization (28% vs. 0%, P = 0.038). CD4 level had no influence on immunization rates.

Conclusions: Sci-B-Vac might achieve better immunization rates among HIV-positive adults compared to the single-antigen vaccine and thus deserves further evaluation in a randomized, double-blind study in this population.

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: DHEAS, the most abundant steroid secreted by the adrenal cortex, is suggested to have an important role in the development of immune reaction by activating T cell function and increasing antibody response, and has been tried as a vaccine adjuvant in elderly people.

Objectives: We examined the correlation between endogenous DHEAS and antibody response in the neonatal period by comparing the serum DHEAS levels with the amount of antibody response against hepatitis B vaccination in neonates.

Methods: Vaccine was administered to 12 healthy infants within 24 hours of birth (day 0), and blood specimens were obtained on days 0 and 30 for determination of anti-hepatitis B surface antibody concentration and DHEAS levels.

Results: DHEAS levels varied widely (range 0.38-3.70 μg/ml, mean±SD 2.14±0.98). While we could identify two groups of patients - those with high DHEAS levels (2.90±0.56) and those with lower levels (1.30±0.56) - there was no correlation between DHEAS levels and the antibody response to hepatitis B vaccine (γ=-0.05).

Conclusions: In neonates, antibody response to hepatitis B vaccine does not correlate with DHEAS serum levels. These results do not support the usage of DHEAS as a vaccine adjuvant in neonates.

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DHEAS= dehydepiandrosterone sulphate