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Enhanced immune response to hepatitis B vaccination through immunization with a Pre-S1/Pre-S2/S vaccine.

Shouval D, Roggendorf H, Roggendorf M - Med. Microbiol. Immunol. (2015)

Bottom Line: Efficacy and safety of recombinant yeast-derived hepatitis B vaccines for prevention of hepatitis B have been demonstrated unequivocally worldwide as reflected in reduction in HBsAg carrier rates and hepatocellular carcinoma.Such vaccines are useful in special risk groups, i.e., in non-responders to conventional HBV vaccines including older adults, obese people, health care workers, patients with renal failure and on dialysis, transplant patients, patients with HIV as well as travelers on short notice to HBV endemic regions.The future of such vaccines depends on their enhanced immunogenicity and cost profile.

View Article: PubMed Central - PubMed

Affiliation: Liver Unit, Hadassah Hospital, Institute for Gastroenterology and Hepatology, Hadassah-Hebrew University, P.O. Box 12000, 91120, Jerusalem, Israel, shouval@hadassah.org.il.

ABSTRACT
Efficacy and safety of recombinant yeast-derived hepatitis B vaccines for prevention of hepatitis B have been demonstrated unequivocally worldwide as reflected in reduction in HBsAg carrier rates and hepatocellular carcinoma. A new generation of recombinant HBV vaccines expressed in mammalian cells containing Pre-S/S epitopes has been developed in several countries. Such vaccines are useful in special risk groups, i.e., in non-responders to conventional HBV vaccines including older adults, obese people, health care workers, patients with renal failure and on dialysis, transplant patients, patients with HIV as well as travelers on short notice to HBV endemic regions. The future of such vaccines depends on their enhanced immunogenicity and cost profile. Sci-B-Vac™ is a mammalian cell-derived recombinant Pre-S1/Pre-S2/S hepatitis B vaccine which has been shown to be highly immunogenic, inducing faster and higher seroprotection rates against HBV with higher anti-HBs levels at lower HBsAg doses as compared to conventional yeast-derived vaccines. Recently, it has been suggested that such Pre-S/S vaccines against HBV might be efficacious not only for prevention but also for intervention in persistent HBV infection. Data obtained in a recent clinical trial conducted in Vietnam in patients with chronic hepatitis B suggest that repeated monthly i.m. injections of the Sci-B-Vac™ co-administered with daily oral lamivudine treatment can suppress HBV replication and lead to anti-HBs seroconversion in ~50 % of treated patients. Optimization of protocols and efficacy of such an intervention, intended to bypass T cell exhaustion and immune tolerance to HBV remains to be explored.

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HBV-DNA reductions at 3 months post-treatment. The percentage of patients with early HBV-DNA reduction (after 3 months) was expressed using two cutoff levels (reductions of >1 log copy/ml and >2 log copies/ml). The asterisk indicates a significant difference between the VAC + LAM and LAM groups (P < 0.05). VAC-recipients of Sci-B-Vac™, V + L-recipients of Sci-B-Vac™ and Lamivudine, LAM recipients of lamivudine. Reproduced by permission Ref. [81]
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Fig6: HBV-DNA reductions at 3 months post-treatment. The percentage of patients with early HBV-DNA reduction (after 3 months) was expressed using two cutoff levels (reductions of >1 log copy/ml and >2 log copies/ml). The asterisk indicates a significant difference between the VAC + LAM and LAM groups (P < 0.05). VAC-recipients of Sci-B-Vac™, V + L-recipients of Sci-B-Vac™ and Lamivudine, LAM recipients of lamivudine. Reproduced by permission Ref. [81]

Mentions: Significant suppression of median viral load from an overall base line of ~106 log copies/ml by at least 1 log copy/ml was observed at 3 months for the VAC + LAM and the LAM treatment groups being maximal for the combination group at a 65 % response rate (median reduction of viral load 2.6 log copies/ml) as compared to 55 % in the LAM group (1.9 log copies/ml) and 18.3 % (1 log copies/ml) in the VAC group, Fig. 6. Furthermore, an overall rate of HBV-DNA suppression <4 log copies/ml was observed in 55 % of the VAC + LAM group as compared to 28.3 % in the monotherapy with LAM. This effect was sustained and still present at month 12, 4 months after administration of the last vaccine dose. These results suggest that co-administration of Sci-B-Vac™ and lamivudine have a synergistic effect on suppression of viral load as compared to vaccination alone or monotherapy with lamivudine. At month 18 post-initiation of treatment, viral load suppression was still documented in 51.7 and 43.4 % of VAC + LAM and LAM recipients, respectively. Yet, from the data presented, it seems that the enhanced viral suppression afforded by administration of Sci-B-Vac™ in the combination group was waning at month 18, when patients were off treatment for 10 months.Fig. 6


Enhanced immune response to hepatitis B vaccination through immunization with a Pre-S1/Pre-S2/S vaccine.

Shouval D, Roggendorf H, Roggendorf M - Med. Microbiol. Immunol. (2015)

HBV-DNA reductions at 3 months post-treatment. The percentage of patients with early HBV-DNA reduction (after 3 months) was expressed using two cutoff levels (reductions of >1 log copy/ml and >2 log copies/ml). The asterisk indicates a significant difference between the VAC + LAM and LAM groups (P < 0.05). VAC-recipients of Sci-B-Vac™, V + L-recipients of Sci-B-Vac™ and Lamivudine, LAM recipients of lamivudine. Reproduced by permission Ref. [81]
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4305084&req=5

Fig6: HBV-DNA reductions at 3 months post-treatment. The percentage of patients with early HBV-DNA reduction (after 3 months) was expressed using two cutoff levels (reductions of >1 log copy/ml and >2 log copies/ml). The asterisk indicates a significant difference between the VAC + LAM and LAM groups (P < 0.05). VAC-recipients of Sci-B-Vac™, V + L-recipients of Sci-B-Vac™ and Lamivudine, LAM recipients of lamivudine. Reproduced by permission Ref. [81]
Mentions: Significant suppression of median viral load from an overall base line of ~106 log copies/ml by at least 1 log copy/ml was observed at 3 months for the VAC + LAM and the LAM treatment groups being maximal for the combination group at a 65 % response rate (median reduction of viral load 2.6 log copies/ml) as compared to 55 % in the LAM group (1.9 log copies/ml) and 18.3 % (1 log copies/ml) in the VAC group, Fig. 6. Furthermore, an overall rate of HBV-DNA suppression <4 log copies/ml was observed in 55 % of the VAC + LAM group as compared to 28.3 % in the monotherapy with LAM. This effect was sustained and still present at month 12, 4 months after administration of the last vaccine dose. These results suggest that co-administration of Sci-B-Vac™ and lamivudine have a synergistic effect on suppression of viral load as compared to vaccination alone or monotherapy with lamivudine. At month 18 post-initiation of treatment, viral load suppression was still documented in 51.7 and 43.4 % of VAC + LAM and LAM recipients, respectively. Yet, from the data presented, it seems that the enhanced viral suppression afforded by administration of Sci-B-Vac™ in the combination group was waning at month 18, when patients were off treatment for 10 months.Fig. 6

Bottom Line: Efficacy and safety of recombinant yeast-derived hepatitis B vaccines for prevention of hepatitis B have been demonstrated unequivocally worldwide as reflected in reduction in HBsAg carrier rates and hepatocellular carcinoma.Such vaccines are useful in special risk groups, i.e., in non-responders to conventional HBV vaccines including older adults, obese people, health care workers, patients with renal failure and on dialysis, transplant patients, patients with HIV as well as travelers on short notice to HBV endemic regions.The future of such vaccines depends on their enhanced immunogenicity and cost profile.

View Article: PubMed Central - PubMed

Affiliation: Liver Unit, Hadassah Hospital, Institute for Gastroenterology and Hepatology, Hadassah-Hebrew University, P.O. Box 12000, 91120, Jerusalem, Israel, shouval@hadassah.org.il.

ABSTRACT
Efficacy and safety of recombinant yeast-derived hepatitis B vaccines for prevention of hepatitis B have been demonstrated unequivocally worldwide as reflected in reduction in HBsAg carrier rates and hepatocellular carcinoma. A new generation of recombinant HBV vaccines expressed in mammalian cells containing Pre-S/S epitopes has been developed in several countries. Such vaccines are useful in special risk groups, i.e., in non-responders to conventional HBV vaccines including older adults, obese people, health care workers, patients with renal failure and on dialysis, transplant patients, patients with HIV as well as travelers on short notice to HBV endemic regions. The future of such vaccines depends on their enhanced immunogenicity and cost profile. Sci-B-Vac™ is a mammalian cell-derived recombinant Pre-S1/Pre-S2/S hepatitis B vaccine which has been shown to be highly immunogenic, inducing faster and higher seroprotection rates against HBV with higher anti-HBs levels at lower HBsAg doses as compared to conventional yeast-derived vaccines. Recently, it has been suggested that such Pre-S/S vaccines against HBV might be efficacious not only for prevention but also for intervention in persistent HBV infection. Data obtained in a recent clinical trial conducted in Vietnam in patients with chronic hepatitis B suggest that repeated monthly i.m. injections of the Sci-B-Vac™ co-administered with daily oral lamivudine treatment can suppress HBV replication and lead to anti-HBs seroconversion in ~50 % of treated patients. Optimization of protocols and efficacy of such an intervention, intended to bypass T cell exhaustion and immune tolerance to HBV remains to be explored.

Show MeSH
Related in: MedlinePlus