Search results for "Hepatitis B vaccine"
showing 10 items of 51 documents
Protein-prime/modified vaccinia virus Ankara vector-boost vaccination overcomes tolerance in high-antigenemic HBV-transgenic mice
2015
Abstract Background Therapeutic vaccination is a novel treatment approach for chronic hepatitis B, but only had limited success so far. We hypothesized that optimized vaccination schemes have increased immunogenicity, and aimed at increasing therapeutic hepatitis B vaccine efficacy. Methods Modified Vaccinia virus Ankara (MVA) expressing hepatitis B virus (HBV) antigens was used to boost protein-prime vaccinations in wildtype and HBV-transgenic (HBVtg) mice. Results Protein-prime/MVA-boost vaccination was able to overcome HBV-specific tolerance in HBVtg mice with low and medium but not with high antigenemia. HBV-specific antibody titers, CD8+ T-cell frequencies and polyfunctionality inverse…
Long-term efficacy of hepatitis B vaccine, booster policy, and impact of hepatitis B virus mutants
2005
The long-term efficacy of hepatitis B vaccine, long-term effectiveness of hepatitis B immunisation programmes, immune memory induced by hepatitis B vaccine, current booster policies, and impact of hepatitis B virus mutants on immunisation programmes were reviewed at the Viral Hepatitis Prevention Board (VHPB) meeting in Sevilla, Spain, March 2004. The main focus was on universal vaccination programmes with data being presented from Italy, Saudi Arabia, Singapore, Spain, Taiwan, Thailand, The Gambia, and USA (Alaska).
N-terminal myristoylation-dependent masking of neutralizing epitopes in the preS1 attachment site of hepatitis B virus
2011
The N-terminally myristoylated preS1 domain of the large hepatitis B surface protein (LHBs) mediates specific attachment of hepatitis B virus (HBV) to hepatocytes. Its B-cell epitopes leading to neutralization of infectivity are not yet characterized.We inserted C- and N-terminal preS1 peptides into the most immunogenic region of HBV core particles, therewith immunized Balb/c mice and determined binding properties and neutralization potential of resulting antibodies in vitro.The particles with preS1 inserts were highly immunogenic and the corresponding anti-preS antibodies strongly bound to HBV particles from chronic carriers infected with different HBV genotypes A-F. However, antibodies bi…
Priming of cytotoxic T cell responses to exogenous hepatitis B virus core antigen is B cell dependent
2003
The hepatitis B virus (HBV) core antigen (HBcAg) has a unique ability to bind a high frequency of naive human and murine B cells. The role of HBcAg-binding naive B cells in the immunogenicity of HBcAg is not clear. The HBcAg-binding properties of naive B cells were characterized using HBcAg particles with mutated spike region (residues 76-85) sequences. Deletion of residues 76-85 (HBcDelta76-85) destroyed naive B cell binding, whereas deletion of residues 79-85 did not. HBcAg particles with an Ile instead of the natural Ala at position 80 did not bind naive B cells, whereas reversion of Ile80--Ala restored B cell binding. Destroying the B cell-binding ability of HBcAg had a marginal effect …
Mosaic particles formed by wild-type hepatitis B virus core protein and its deletion variants consist of both homo- and heterodimers.
2003
AbstractCo-expression in Escherichia coli of wild-type (wt) hepatitis B virus core protein (HBc) and its naturally occurring variants with deletions at amino acid positions 77–93 or 86–93 leads to formation of mosaic particles, which consist of three dimer subunit compositions. These compositions are wt/variant HBc heterodimers and two types of homodimers, formed by wt HBc or the variant HBc themselves. Mosaic particles were found also when both HBc deletion variants 77–93 and 86–93 were co-expressed in E. coli. These findings are discussed in terms of their significance for hepatitis B virus pathogenesis and prospective use of mosaic particles in vaccine development.
Prevention of Hepatocellular Carcinoma
2005
The accuracy and the reliability of well-recognized clinical, virologic, histologic, and molecular risk factors for HCC are still insufficient; thus, accurate risk prediction of developing cancer in individual patients remains an elusive goal. Future directions in chemprevention of HCC will be on the development of molecular risk models and of new chemopreventive agents. The design of targeted molecular therapies may need to be tailored to the specific molecular phenotype of a specific HCC. Studies examining multiple genes and proteins (genomics and proteomics) in the same HCCs will be required to evaluate this possibility thoroughly. In the setting of primary prevention, the epidemiologic …
Long-term pertussis-specific immunity after primary vaccination with a combined diphtheria, tetanus, tricomponent acellular pertussis, and hepatitis …
2001
ABSTRACT The aim of this study was to compare pertussis-specific humoral and cellular immunity in children 5 years after a primary vaccination with a combined diphtheria, tetanus, tricomponent acellular pertussis, and hepatitis B vaccine (DTaP-HBV; InfanrixHepB; SmithKline Beecham) with immunity after natural infection. The subjects were 38 children aged 5 to 6 years who received DTaP-HBV at 3, 5, and 11 months of life and 21 subjects of similar ages and sex who acquired pertussis in the first year of life. Immunoglobulin G (IgG) antibody titers against Bordetella pertussis antigens, peripheral blood mononuclear cell-specific proliferation, and the secretion of cytokines were evaluated. Aft…
Long-term pertussis-specific immune responses to a combined diphtheria, tetanus, tricomponent acellular pertussis and hepatitis B vaccine in pre-term…
2002
Abstract Immunoglobulin G (IgG) antibody titres against pertussis antigens, Bordetella pertussis-specific proliferation and cytokine production by peripheral blood mononuclear cells (PBMCs) were evaluated at the age of 5–6 years in 13 children who had been pre-term infants with a gestational age (GA) of ≤31 weeks, 10 who had been pre-term infants with a GA of 32–37 weeks, and 15 who had been term infants with a GA of 38–42 weeks. All of the infants had been immunised with a combined diphtheria, tetanus, tricomponent acellular pertussis and hepatitis B vaccine (DTaP–HBV) at 3, 5, and 11 months of post-natal age. Our results show that the long-term immune responses induced by primary pertussi…
Neonatal vaccination with an acellular pertussis vaccine accelerates the acquisition of pertussis antibodies in infants
2007
Objectives Because young infants are at highest risk of pertussis complications, this study assessed whether neonatal acellular pertussis (aP) vaccination could provide earlier immunity. Study design Neonates (n = 121) were randomly assigned (1:1) to receive either aP or hepatitis B vaccine (HBV) (controls) vaccine at birth, followed by vaccination with DTaP-HBV-IPV/Hib at 2, 4 and 6 months. Immune responses were measured. Reactogenicity was assessed for 7 days after each dose. Results The aP birth dose was followed by few adverse events. Reactogenicity of subsequent vaccine doses did not differ between groups. Seven serious adverse events were reported from each group; none were related to…
The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on hepatitis B vaccination in haemodialysis patients.
1996
Haemodialysis patients often fail to respond to hepatitis B vaccination. In this pilot study, 15 patients previously non-responsive to at least three 40 micrograms doses of hepatitis B vaccine were given 0.5, 5 or 10 micrograms kg-1 granulocyte-macrophage colony-stimulating factor (GM-CSF) subcutaneously 24 h prior to booster vaccination with a hepatitis B vaccine. Seven of the 15 patients developed antibody to hepatitis B surface antigen (HBsAb) (35-7240 IU L-1) upon initial vaccination with GM-CSF and two of four individuals responded with low HBsAb titres of 15 and 60 IU L-1 when revaccinated with hepatitis B surface antigen (HBsAg) and twice the dose of GM-CSF. The application of GM-CSF…