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2,855 result(s) for "Hepatitis B Surface Antigens - immunology"
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Effectiveness of a hepatitis E vaccine against medically-attended symptomatic infection in HBsAg-positive adults from a test-negative design study
The effectiveness of the hepatitis E vaccine in high-risk groups, such as chronic hepatitis B (CHB) patients, remains understudied. A key clinical manifestation of CHB is the persistent positivity of hepatitis B surface antigen (HBsAg). We conducted a test-negative design study involving 2,926 HBsAg-positive individuals (born 1941–1991; median age 49.0; male-to-female ratio of 1.4), identified through a hepatitis surveillance system, as part of the phase 3 trial (NCT01014845) of the recombinant hepatitis E vaccine HEV 239 (Hecolin). This system monitored suspected hepatitis cases and performed diagnoses across 11 townships in Dongtai, Jiangsu, China, from 2007 to 2017. Vaccine effectiveness of HEV 239 was assessed by comparing vaccination status between confirmed 96 hepatitis E cases and 2830 test-negative controls, using logistic regression adjusted for sex and age. We found that HEV 239 vaccination was associated with a reduced risk of hepatitis E among HBsAg-positive individuals, with an estimated effectiveness of 72.1% [95% confidence interval (CI) 11.2–91.2], and 81.5% (95% CI 35.9–94.6) among phase 3 trial participants. Our findings show that HEV 239 is highly effective in HBsAg-positive adults, supporting its future recommended use in this population. Effectiveness of the hepatitis E vaccine HEV 239 amongst high-risk groups isn’t well studied. Here, Zhuang et al. analyse a decade of surveillance data (2007–2017) from Dongtai, China, and estimate HEV 239 effectiveness of 72% amongst hepatitis B virus infected people.
A three antigen hepatitis B vaccine induces T cells to Pres1 and Pres2 which correlate with anti HBs antibody titers: An investigation into the immunological mechanisms contributing to high anti-HBs titers
PreHevbrio® is a 3-antigen HBV vaccine (3-A-HBV) engineered to express the three HBV envelope proteins; the small ‘S' hepatitis B surface antigen (SHBs or HBsAg), the middle pre-S2 + HBsAg (MHBs) and the large PreS1 + PreS2 + HBsAg (LHBs) antigens. 3-A-HBV has been shown to induce superior and more durable antibody responses relative to a 1-A-HBV despite containing half the ‘S' antigen dose. To explain the mechanism(s) behind the high immunogenicity, the potential influence of mammalian glycosylation, HBs antigen conformation, anti-HBs epitope binding profiles and T-cell responses to the PreS antigens were investigated. In this paper, we demonstrate that glycosylation status does not play a role in the increased immunogenicity of the 3-A-HBV, but that the 3-A-HBV particles are able to induce T cell responses to PreS1 and PreS2 antigens. Epitope mapping demonstrated that the 3-A-HBV particles are inherently more antigenic than 1-A-HBV particles, leading to quantitative differences in the anti-HBs antibody response. Further, we demonstrate that the T cell responses significantly correlate with the higher observed anti-HBs titers and may contribute to the higher and more durable anti-HBs titers. This trial is registered at Clinicaltrials.gov (NCT03393754) and EudraCT (2017–001819-36). •PreHevbrio is a 3-antigen HBV vaccine shown to induce high anti-HBs titers following vaccination.•Immunological aspects of 3-A-HBV were studied to reveal the mechanisms behind the immunogenicity.•Epitope mapping revealed that 3-A-HBV particles are more antigenic than 1-A-HBV particles.•T cell responses may contribute to the higher and more durable anti-HBs titers.
Comparison of safety and immunogenicity of two doses of investigational hepatitis B virus surface antigen co-administered with an immunostimulatory phosphorothioate oligodeoxyribonucleotide and three doses of a licensed hepatitis B vaccine in healthy adults 18–55 years of age
► Two doses of an HBV-ISS demonstrated superior immunogenicity to three doses of HBV-Eng measured at week 28. ► HBV-ISS had a safety profile that was similar to the currently licensed HBV-Eng although injection-site reactions were more common. ► HBV-ISS achieved higher levels of protection after the first and second doses. The currently licensed aluminum-hydroxide-adjuvanted hepatitis B vaccines require three doses over a 6-month period to achieve high rates of protection in adults. We compared tolerability and immunogenicity of two doses of an investigational hepatitis B vaccine using hepatitis B surface antigen adjuvanted with an immunostimulatory phosphorothioate oligodeoxyribonucleotide (HBV-ISS) to three doses of a licensed alum-adjuvanted vaccine (HBV-Eng). In this randomized, observer-blind study, healthy adults received two doses of HBV-ISS at 0 and 4 weeks or three doses of HBV-Eng at 0, 4, and 24 weeks. The primary immunogenicity endpoint was the seroprotection rate (antibody≥10mIU/mL) 8 weeks after the second dose of HBV-ISS compared to 4 weeks after the third dose of HBV-Eng. A total of 2415 participants were randomized in a ratio of 3:1 to HBV-ISS (n=1809) and HBV-Eng (n=606). The percentage of subjects exhibiting a seroprotective immune response at the primary time point was significantly higher (95.1%) for HBV-ISS than for HBV-Eng (81.1%). Superiority of the seroprotective rates for HBV-ISS was demonstrated at all time points measured. Geometric mean concentrations were also significantly higher in the HBV-ISS group at all time points measured except at week 28 (24 weeks post-second dose of HBV-ISS and 4 weeks post-third dose HBV-ISS) at which time the antibody concentrations were similar. Both vaccines were welltolerated although injection-site reactions were reported at a higher rate in HBV-ISS recipients. A short, two-dose regimen of HBV-ISS induced a superior antibody response than a three-dose regimen of a licensed hepatitis B vaccine and was well tolerated.
Immunogenicity and safety of an investigational hepatitis B vaccine with a Toll-like receptor 9 agonist adjuvant (HBsAg-1018) compared to a licensed hepatitis B vaccine in healthy adults 40–70 years of age
•Phase 3 trial of investigational hepatitis B vaccine in adults 40–70years old.•2 doses of HBsAg-1018 demonstrated superior seroprotection to 3 doses of HBsAg-Eng.•HBsAg-1018 induced earlier seroprotection than HBsAg-Eng.•The safety profile of HBsAg-1018 was similar to that of HBsAg-Eng. The currently licensed hepatitis B vaccines have limitations including hyporesponsiveness in older adults, poor compliance, and the extended time for most persons to develop seroprotection (e.g. >6months). A vaccine containing HBsAg combined with a Toll-like receptor 9 agonist adjuvant (HBsAg-1018) has been developed to overcome these limitations. A Phase 3, multicenter, randomized, subject- and observer-blinded, active-controlled trial was conducted among healthy subjects 40–70years of age comparing the immunogenicity and safety of two doses of HBsAg-1018 at 0 and 4weeks to three doses of licensed hepatitis B vaccine, HBsAg-Eng, at 0, 4, and 24weeks. The primary immunogenicity endpoint was noninferiority of the seroprotection rate (SPR; % with anti-HBs≥10mIU/mL) of HBsAg-1018 compared to the SPR of HBsAg-Eng at 8 weeks following the last dose of vaccine. Conditional upon meeting noninferiority, superiority of HBsAg-1018 over HBsAg-Eng was assessed. Safety was compared between the two vaccines. At the primary endpoint, the SPR for the HBsAg-1018 group (90.0%) was superior to the SPR for the HBsAg-Eng group (70.5%) with an SPR difference of 19.5% (95% CI, 14.7%, 24.7%). At week 28 when the SPR peaked in the HBsAg-Eng group (72.8%), the SPR in the HBsAg-1018 group (94.8%) was significantly higher than in the HBsAg-Eng group. The SPR in the HBsAg-1018 group was significantly higher than in the HBsAg-Eng group at each study visit from week 4 through week 52. The safety profiles for the two vaccines were similar. When compared to the HBsAg-Eng three-dose regimen given at 0, 1, and 6months, HBsAg-1018 demonstrated superior seroprotection with only two doses at 0 and 1month. The safety profile of HBsAg-1018 was comparable to that of the licensed vaccine, HBsAg-Eng. HBsAg-1018 would provide a significant public health contribution toward the prevention of hepatitis B infection.
Epidemiology of blood-borne viral infections in Afghanistan
Although a few studies have been done on transmissible blood-borne viral infections in high-risk groups, little attention has been given to assessing the infection status of the general population in Afghanistan. To investigate the epidemiological status in the general population, we tested the serological markers of hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis delta virus (HDV), human immunodeficiency virus 1 (HIV-1) and human T-cell leukemia virus (HTLV) infections. In total, 492 samples were selected randomly from Nangarhar, Herat, Mazar-e Sharif, Kandahar, and Kabul from subjects between 25 and 70 years old. The samples were tested for the presence of HBsAg, anti-HBs, anti-HBc, anti-HDV, anti-HCV, anti-HIV-1 and anti-HTLV I/II antibodies using chemiluminescent immunoassays on Abbott Architect automated platforms. In addition, 220 HBsAg-positive samples identified among 5897 samples from the general population of the same regions of Afghanistan were included in the study and tested for both HBsAg and anti-HDV to investigate HDV prevalence in the country. Viral loads of HBV, HCV and HDV were determined in all seropositive samples using Ampliprep/Cobas TaqMan HBV, HCV, Test Roche (CA, USA), and an in-house method, respectively. Out of 492 samples, 31 (6.3%), 136 (27.6%) and 149 (30.3%) were found to be positive for HBsAg, anti-HBs and anti-HBc, respectively. Anti-HDV positivity was detected in five (2.1%) out of 234 HBsAg-positive samples (including 14 of the randomly selected samples that were not among the 220 previously identified as HBsAg positive). Only eight out of 492 (1.6%) subjects were positive for anti-HCV antibodies. Seven out of 489 (1.4%) were positive for anti-HIV-1 antibodies, and three out of 466 cases (0.6%) were positive for anti-HTLV I/II antibodies. These results suggest that Afghanistan is an intermediate endemic region for HBV, HDV and HCV infection. The prevalence of HIV-1 seems to be significantly higher than the global prevalence and that of the eastern Mediterranean region. In addition, the HTLV I/II screening results suggest that these viruses should be monitored in Afghanistan to confirm the trend observed in the current study.
No association between IFNL3 (IL28B) genotype and response to peginterferon alfa-2a in HBeAg-positive or -negative chronic hepatitis B
It has yet to be firmly established whether host IFNL3 (IL28B) genotype influences interferon responsiveness in patients with chronic hepatitis B. We investigated associations between single-nucleotide polymorphisms (SNPs) in the IFNL3 region and response to peginterferon alfa-2a in 701 patients enrolled in three large, randomized, international studies. Responses were defined as hepatitis B surface antigen (HBsAg) loss and/or hepatitis B e antigen (HBeAg) seroconversion plus hepatitis B virus (HBV) DNA <2000 IU/ml in HBeAg-positive patients, and HBsAg loss and/or HBV DNA <2000 IU/ml in HBeAg-negative patients (24 weeks after end of treatment). Associations between treatment response and the number of copies of the poor-response allele at three SNPs (rs8099917, rs12980275, rs12979860) were explored with logistic regression models in Asian and white patients. The HBeAg-positive and -negative populations comprised 465 (92% Asian, 50% HBV genotype C) and 236 (79% Asian, 41% HBV genotype C) patients, respectively, and had respective response rates of 26% and 47%. The IFNL3 genotype was strongly associated with ethnicity. There was no association between IFNL3 genotype and treatment response in HBeAg-positive or -negative patients. Independent predictors of treatment response were: sex, HBV DNA level and alanine aminotransferase level in HBeAg-positive Asian patients; age in HBeAg-negative Asian patients; and HBV DNA in HBeAg-negative white patients. This is the largest analysis to date of associations between IFNL3 genotype and peginterferon response in patients with chronic hepatitis B. The data suggest that IFNL3 polymorphism is not a major determinant of the response to peginterferon alfa-2a in either HBeAg-positive or HBeAg-negative patients.
Vaccine Adjuvant Systems containing monophosphoryl lipid A and QS-21 induce strong humoral and cellular immune responses against hepatitis B surface antigen which persist for at least 4 years after vaccination
•HBsAg in combination with MPL/QS-21 Adjuvant Systems was highly immunogenic.•CD4+ T-cell, memory B-cell and antibody responses persisted for at least 4 years.•Vaccine adjuvant systems offer potential for challenging diseases or populations. Recombinant hepatitis B surface antigen (HBsAg) was used as a model antigen to evaluate persistence of cellular and humoral immune responses when formulated with three different Adjuvant Systems containing 3-O-desacyl-4′-monophosphoryl lipid A (MPL) and QS-21, in an oil-in-water emulsion (AS02B and AS02V), or with liposomes (AS01B). This is an open, 4-year follow-up of a previous randomised, double-blind study. Healthy subjects aged 18–40 years received three vaccine doses on a month 0, 1, 10 schedule and were initially followed for 18 months. A total of 93 subjects (AS02B: n=30; AS02V: n=28; AS01B: n=35) were enrolled in this follow-up and had an additional blood sample taken at Year 4 (NCT02153320). The primary endpoint was the frequency of HBsAg-specific CD4+ and CD8+ T-cells expressing cytokines upon short-term in vitro stimulation of peripheral blood mononuclear cells with HBsAg-derived peptides. Secondary endpoints were anti-HBs antibody titres and frequency of HBsAg-specific memory B-cells. A strong and persistent specific CD4+ T-cell response was observed at Year 4 in all groups. HBsAg-specific CD4+ T-cells expressed mainly CD40L and IL-2, and to a lesser extent TNF-α and IFN-γ. HBsAg-specific CD8+ T-cells were not detected in any group. A high, persistent HBsAg-specific humoral immune response was observed in all groups, with all subjects seroprotected (antibody titre ≥10mIU/mL) at Year 4. The geometric mean antibody titre at Year 4 was above 100,000mIU/mL in all groups. A strong memory B-cell response was observed post-dose 2, which tended to increase post-dose 3 and persisted at Year 4 in all groups. The MPL/QS-21/HBsAg vaccine formulations induced persistent immune responses up to 4 years after first vaccination. These Adjuvant Systems offer potential for combination with recombinant, synthetic or highly purified subunit vaccines, particularly for vaccination against challenging diseases, or in specific populations, although additional studies are needed.
Demonstration of safety and enhanced seroprotection against hepatitis B with investigational HBsAg-1018 ISS vaccine compared to a licensed hepatitis B vaccine
► Adults ≥40 years of age are commonly hypo-responsive to licensed HBV vaccines. ► HBsAg-1018 ISS elicits earlier, higher and longer lasting antibody than Engerix-B. ► 2 doses of HBsAg-1018 ISS provides superior protection over 3 doses of Engerix-B. ► HBsAg-1018 ISS was well tolerated with a similar safety profile as Engerix-B. ► HBsAg-1018 ISS may be more effective in hypo-responsive populations. Adults 40 years of age and older have been shown to be hypo-responsive immunologically to the currently available hepatitis B virus (HBV) vaccines. Three intramuscular doses of a Toll-like receptor 9 agonist, 1018 immunostimulatory sequence (1018 ISS) adjuvant, combined with recombinant hepatitis B surface antigen (HBsAg) demonstrated faster, superior, and more durable seroprotection than three doses of a licensed comparator HBV vaccine (Engerix-B®). This investigational vaccine, HBsAg-1018 ISS, was well tolerated with a safety profile similar to the comparator vaccine. These results suggest that HBsAg-1018 may be more effective in this hypo-responsive population.
Safety of a two-dose investigational hepatitis B vaccine, HBsAg-1018, using a toll-like receptor 9 agonist adjuvant in adults
Hepatitis B virus infection remains an important global public health problem. Approved alum-adjuvanted vaccines are well tolerated but require three doses and have reduced immunogenicity in adults. A two-dose vaccine containing hepatitis B surface antigen combined with a novel, Toll-like receptor 9 agonist adjuvant (HBsAg-1018 [HEPLISAV–B®]) has demonstrated significantly higher seroprotection rates than a three dose vaccine. A post hoc analysis compared the safety of HBsAg-1018 with HBsAg-Eng (Engerix-B®), in three randomized, observer-blinded, active-controlled, multi-center phase 3 trials in adults. HBsAg-1018 was administered intramuscularly at weeks 0 and 4 and placebo at week 24 and HBsAg-Eng at weeks 0, 4, and 24. Post-injection reactions, adverse events, medically attended adverse events, and new-onset immune-mediated adverse events were balanced between vaccine groups. Anti-nuclear antibodies, anti-double stranded DNA antibodies, anti-neutrophil cytoplasmic antibodies, and antiphospholipid antibodies were balanced between groups. A transient increase in anti-beta2 glycoprotein 1 IgM was observed in the HBsAg-1018 group but was not associated with a thrombotic event. Serious adverse events and deaths were generally balanced between groups. HBsAg-1018 had a similar safety profile to HBsAg-Eng. With improved immunogenicity and fewer doses over a shorter time, HBsAg-1018 has the potential to provide improved seroprotection and a significant public health benefit to adults 18 years of age or older.
Immunogenicity and safety of an investigational hepatitis B vaccine with a toll-like receptor 9 agonist adjuvant (HBsAg-1018) compared with a licensed hepatitis B vaccine in patients with chronic kidney disease
•Phase 3 trial of investigational hepatitis B vaccine in chronic kidney disease.•HBsAg-1018 induced superior seroprotection to HBsAg-Eng.•HBsAg-1018 induced more durable seroprotection than HBsAg-Eng.•The safety profile of HBsAg-1018 was similar to that of HBsAg-Eng. Hemodialysis patients are at increased risk of hepatitis B virus (HBV) infection and patients with chronic kidney disease (CKD) are commonly hyporesponsive to HBV vaccines. Current recommendations for CKD patients are to utilize 4 double-doses (2×20mcg HBsAg) of a licensed hepatitis B vaccine (HBsAg-Eng). An observer-blind, randomized, active-controlled, parallel group, multicenter trial was conducted among 521 patients 18–75 years of age with CKD, comparing 3 single doses of an investigational hepatitis B vaccine (20mcg rHBsAg+3000mcg 1018, a toll-like receptor 9 agonist) given at 0, 4, and 24 weeks to 4 double-doses of HBsAg-Eng (2×20mcg rHBsAg+500mcg alum) given at 0, 4, 8, and 24 weeks (total of 8 injections). Participants were followed for 1 year. Among 467 participants in the modified intent-to-treat population, at the primary endpoint at week 28, the seroprotection rate (SPR: % with anti-HBs≥10mIU/mL) in the HBsAg-1018 group (89.9%) met criteria for noninferiority and superiority to the SPR in the HBsAg-Eng group (81.8%). At week 28, the percentage of participants with anti-HBs≥100mIU/mL in theHBsAg-1018 group (73.6%) was significantly higher than in the HBsAg-Eng group (63.2%). In addition, the geometric mean concentration of anti-HBs in the HBsAg-1018 group (587.1mIU/mL) was significantly higher than in the HBsAg-Eng group (156.5mIU/mL). At weeks 8 and 12 after the first study injection, SPRs in the HBsAg-1018 group were significantly higher than in the HBsAg-Eng group. At 52 weeks, the immune response toHBsAg-1018 remained higher than to HBsAg-Eng. HBsAg-1018 was generally well tolerated and had a similar safety profile to HBsAg-Eng. In CKD patients, 3 doses of HBsAg-1018 induced significantly higher seroprotection, earlier seroprotection, and more durable seroprotection than 4 double doses of HBsAg-Eng.