Immunopotentiating and Delivery Systems for HCV Vaccines

Development of preventive vaccines against hepatitis C virus (HCV) remains one of the main strategies in achieving global elimination of the disease. The effort is focused on the quest for vaccines capable of inducing protective cross-neutralizing humoral and cellular immune responses, which in turn dictate the need for rationally designed cross-genotype vaccine antigens and potent immunoadjuvants systems. This review provides an assessment of the current state of knowledge on immunopotentiating compounds and vaccine delivery systems capable of enhancing HCV antigen-specific immune responses, while focusing on the synergy and interplay of two modalities. Structural, physico-chemical, and biophysical features of these systems are discussed in conjunction with the analysis of their in vivo performance. Extreme genetic diversity of HCV-a well-known hurdle in the development of an HCV vaccine, may also present a challenge in a search for an effective immunoadjuvant, as the effort necessitates systematic and comparative screening of rationally designed antigenic constructs. The progress may be accelerated if the preference is given to well-defined molecular immunoadjuvants with greater formulation flexibility and adaptability, including those capable of spontaneous self-assembly behavior, while maintaining their robust immunopotentiating and delivery capabilities.

In Vivo and In Vitro Potency of Polyphosphazene Immunoadjuvants with Hepatitis C Virus Antigen and the Role of Their Supramolecular Assembly

Two well-defined synthetic polyphosphazene immunoadjuvants, PCPP and PCEP, were studied for their ability to potentiate the immune response to the hepatitis C virus (HCV) E2 glycoprotein antigen in vivo. We report that PCEP induced significantly higher serum neutralization and HCV-specific IgG titers in mice compared to other adjuvants used in the study: PCPP, Alum, and Addavax. PCEP also shifted the response toward the desirable balanced Th1/Th2 immunity, as evaluated by the antibody isotype ratio (IgG2a/IgG1). The in vivo results were analyzed in the context of antigen-adjuvant molecular interactions in the system and in vitro immunostimulatory activity of formulations. Asymmetric flow field flow fractionation (AF4) and dynamic light scattering (DLS) analysis showed that both PCPP and PCEP spontaneously self-assemble with the E2 glycoprotein with the formation of multimeric water-soluble complexes, which demonstrates the role of polyphosphazene macromolecules as vaccine delivery vehicles. Intrinsic in vitro immunostimulatory activity of polyphosphazene adjuvants, which was assessed using a mouse macrophage cell line, revealed comparable activities of both polymers and did not provide an explanation of their in vivo performance. However, PCEP complexes with E2 displayed greater stability against agglomeration and improved in vitro immunostimulatory activity compared to those of PCPP, which is in line with superior in vivo performance of PCEP. The results emphasize the importance of often neglected antigen-polyphosphazene self-assembly mechanisms in formulations, which can provide important insights on their in vivo behavior and facilitate the establishment of a structure-activity relationship for this important class of immunoadjuvants.

Design of a native-like secreted form of the hepatitis C virus E1E2 heterodimer

Hepatitis C virus (HCV) is a major worldwide health burden, and a preventive vaccine is needed for global control or eradication of this virus. A substantial hurdle to an effective HCV vaccine is the high variability of the virus, leading to immune escape. The E1E2 glycoprotein complex contains conserved epitopes and elicits neutralizing antibody responses, making it a primary target for HCV vaccine development. However, the E1E2 transmembrane domains that are critical for native assembly make it challenging to produce this complex in a homogenous soluble form that is reflective of its state on the viral envelope. To enable rational design of an E1E2 vaccine, as well as structural characterization efforts, we have designed a soluble, secreted form of E1E2 (sE1E2). As with soluble glycoprotein designs for other viruses, it incorporates a scaffold to enforce assembly in the absence of the transmembrane domains, along with a furin cleavage site to permit native-like heterodimerization. This sE1E2 was found to assemble into a form closer to its expected size than full-length E1E2. Preservation of native structural elements was confirmed by high-affinity binding to a panel of conformationally specific monoclonal antibodies, including two neutralizing antibodies specific to native E1E2 and to its primary receptor, CD81. Finally, sE1E2 was found to elicit robust neutralizing antibodies in vivo. This designed sE1E2 can both provide insights into the determinants of native E1E2 assembly and serve as a platform for production of E1E2 for future structural and vaccine studies, enabling rational optimization of an E1E2-based antigen.

Hepatitis B virus prevalence and risk factors in hard-to-reach Turkish population living in Belgium: A protocol for screening

BACKGROUND

Hepatitis B virus (HBV) infection is an important public health problem in the Turkish population, that is, one of the largest migrant populations in Europe. With the introduction of cost-effective antiviral treatments in the past decade, there is a need to identify HBV-infected patients who may benefit from treatment. This study describes the design of a study to assess the HBV prevalence in the Turkish population living in Belgium. Additionally, we will determine the risk factors of HBV infection and the uptake of screening, vaccination, and antiviral treatment in this hard-to-reach Turkish population.

METHODS

A longitudinal, epidemiological study will be conducted in the region Middle Limburg Belgium, where the Turkish adult population, 18 years of age and older, will be screened for hepatitis B surface antigen (HBsAg), antibodies against HBsAg (anti-HBs), and antibodies against hepatitis B core antigen (anti-HBc). Educational meetings concerning viral hepatitis B will be organized and there will be 3 ways to be screened for HBV: immediately after the educational meetings, at the Outpatient Hepatology Department of Ziekenhuis Oost-Limburg, and at home visits. Subsequently, participants will be asked to fill in a questionnaire regarding sociodemographic factors, migration history, risk factors for HBV infection (e.g., sharing toothbrushes, HBV-infected family member), and HBV vaccination status. Six months after screening, HBsAg-positive patients will be assessed whether they are under follow-up at the general practitioner or hepatologist. We will also gather information regarding the uptake of vaccination in nonimmunized subjects.

DISCUSSION

This study will provide information about the HBV prevalence and distribution of the stages of liver disease in the Turkish population in Belgium. By determining the risk factors for HBV infection, subgroups with an increased prevalence of HBV infection can be identified.

CLINICAL TRIAL NUMBER

This clinical trial is registered at clinicaltrials.gov (NCT03396458).

Immunogenicity and safety of an accelerated hepatitis E vaccination schedule in healthy adults: a randomized, controlled, open-label, phase IV trial

OBJECTIVES

This study aimed to evaluate the immunogenicity and safety of a hepatitis E (HE) vaccine using an accelerated vaccination schedule (vaccine doses at 0, 7 and 21 days).

METHODS

A total of 126 participants aged ≥18 years were randomly assigned to receive the hepatitis E virus vaccine in either the accelerated group (0, 7 and 21 days) or the routine group (0, 1 and 6 months). Serology samples were obtained at 0, 21, 28 and 51 days, and 7 months in the accelerated group, or 0, 1, 2 and 7 months in the routine group after the first vaccine injection. Adverse events (AEs) reported during the whole study were analysed.

RESULTS

A total of 126 participants were randomized, 63 for each group. Sixty-two participants in the accelerated group and 63 in the routine group received at least one dose of vaccine; 57 and 63 participants received all three doses and were included in per-protocol set, respectively. In the per-protocol population, at 1 month after the last dose (accelerated group at 51 days versus routine group at 7 months), the seropositive rates were both 100% (57/57 and 63/63, respectively), and the geometric mean concentrations (GMCs) were 8.51 WHO units/mL (95% CI 6.73-10.76) in the accelerated group and 9.67 WHO units/mL (95% CI 7.67-12.20) in the routine group. The ratio of the accelerated group GMC to the routine group GMC was 0.88 (95% CI 0.61-2.17, lower limit of 95% CI > 0.5), indicating that the accelerated vaccination schedule was non-inferior to the routine one. The overall incidence rates of solicited AEs in the accelerated and routine groups were 32.26% (20/62) and 30.16% (19/63), respectively (p 0.800). Most AEs were moderate.

CONCLUSIONS

An accelerated schedule is safe and provides protective antibodies in a shorter time compared with the routine schedule. The accelerated schedule should be recommended to adults who are travelling on short notice to an HE-endemic area or during an HE outbreak (Clinical Trial Registration. NCT03168412).

Interrogation of Antigen Display on Individual Vaccine Nanoparticles for Achieving Neutralizing Antibody Responses against Hepatitis C Virus

Elicitation of neutralizing antibody responses against hepatitis C virus (HCV) has been a challenging goal. While the E2 subunit of the HCV envelope glycoprotein complex is a promising target for generating cross-genotype neutralizing antibodies, vaccinations with soluble E2 immunogens generally induce weak neutralizing antibody responses. Here, E2 immunogens (i.e., E2.661 and E2c.661) were loaded into lipid-based nanovaccines and examined for induction of neutralizing antibody responses. Compared with soluble E2 immunogens, E2 nanoparticles elicited 6- to 20-fold higher E2-specific serum IgG titers in mice. Importantly, E2 vaccine nanoparticles analyzed at a single particle level with a flow cytometry-based method revealed interesting dynamics between epitope display on the surfaces of nanoparticles in vitro and induction of neutralizing antibody responses in vivo. E2c.661 nanoparticles that are preferentially bound by a broadly neutralizing antibody, HCV1, in vitro elicit neutralizing antibody responses against both autologous and heterologous HCV virions in vivo. In stark contrast, E2.661 nanoparticles with reduced HCV1-antibody binding in vitro mainly induce autologous neutralizing antibody responses in vivo. These results show that rationale antigen design coupled with interrogation of epitope display on vaccine nanoparticles at a single particle level may aid in vaccine development toward achieving neutralizing antibody responses in vivo.

Reactive and pre-emptive vaccination strategies to control hepatitis E infection in emergency and refugee settings: A modelling study

BACKGROUND

Hepatitis E Virus (HEV) is the leading cause of acute viral hepatitis globally. Symptomatic infection is associated with case fatality rates of ~20% in pregnant women and it is estimated to account for ~10,000 annual pregnancy-related deaths in southern Asia alone. Recently, large and well-documented outbreaks with high mortality have occurred in displaced population camps in Sudan, Uganda and South Sudan. However, the epidemiology of HEV is poorly defined, and the value of different immunisation strategies in outbreak settings uncertain. We aimed to estimate the critical epidemiological parameters for HEV and to evaluate the potential impact of both reactive vaccination (initiated in response to an epidemic) and pre-emptive vaccination.

METHODS

We analysed data from one of the world's largest recorded HEV epidemics, which occurred in internally-displaced persons camps in Uganda (2007-2009), using transmission dynamic models to estimate epidemiological parameters and assess the potential impact of reactive and pre-emptive vaccination strategies.

RESULTS

Under baseline assumptions we estimated the basic reproduction number of HEV in three separate camps to range from 3.7 (95% Credible Interval [CrI] 2.8, 5.1) to 8.5 (5.3, 11.4). Mean latent and infectious periods were estimated to be 34 (95% CrI 28, 39) and 40 (95% CrI 23, 71) days respectively. Assuming 90% vaccine coverage, reactive two-dose vaccination of those aged 16-65 years excluding pregnant women (for whom vaccine is not licensed), if initiated after 50 reported cases, led to mean camp-specific reductions in mortality of 10 to 29%. Pre-emptive vaccination with two doses reduced mortality by 35 to 65%. Both strategies were more effective if coverage was extended to groups for whom the vaccine is not currently licensed. For example, two dose pre-emptive vaccination, if extended to include pregnant women, led to mean reductions in mortality of 66 to 82%.

CONCLUSIONS

HEV has a high transmission potential in displaced population settings. Substantial reductions in mortality through vaccination are expected, even if used reactively. There is potential for greater impact if vaccine safety and effectiveness can be established in pregnant women.

Live attenuated duck hepatitis virus vaccine in breeder ducks: Protective efficacy and kinetics of maternally derived antibodies

Duck viral hepatitis type I is a rapidly spreading infection lethal in young ducklings, caused by the duck hepatitis A virus (DHAV). Vaccination of breeder ducks is a common practice to control DHAV. However, maintaining proper maternal antibody levels in large flocks is difficult. Therefore, a simple vaccination strategy that can induces stable high antibody levels through mass vaccination is desirable. We evaluated a DHAV vaccination strategy for breeder ducks involving oral administration under field conditions, and examined the kinetics of antibody response in the ducks and their progeny. The strategy included a primary intramuscular vaccination, followed by secondary and tertiary oral vaccinations. Five weeks after the primary vaccination, virus-neutralizing antibody titers increased by 8.4 ± 1.3 log₂. The titers remained stable at around 9.0 ± 1.1 log₂ for up to 36 weeks. None of the progeny died when challenged with virulent DHAV at 1, 7 or 14 days of age. The transfer percentage of antibodies from the breeder ducks to their progeny was 12.8 ± 3.0%. When antibody levels of the progeny were measured from the day of hatching to 20 days of age, the levels steadily declined, reaching a mean titer of 0 log₂ at 20 days. The half-life of the maternally derived antibodies against DHAV was 3.4 ± 1.1 days. Our vaccination strategy might be effective in breeder ducks because it can be easily applied and induced strong immunity. Moreover, our results might provide a foundation for the mechanistic study of maternally derived antibodies in passive protection.

How far are we from viral hepatitis elimination service coverage targets?

INTRODUCTION

In 2016, the Global Health Sector Strategy (GHSS) on viral hepatitis called for elimination of viral hepatitis as a major public health threat by 2030 (i.e. 90% reduction in incidence and 65% in mortality). In 2017, WHO's first-ever Global Hepatitis Report presented the baseline values for each of the core indicators of the strategy. We review the challenges and opportunities that lie ahead in order to reach the 2030 service coverage targets.

DISCUSSION

Three-dose coverage of hepatitis B vaccine in infancy reached 84% in 2015 (2030 target: 90%); however, only 39% received the timely birth dose (2030 target: 90%). Blood safety (97% of blood units screened with quality assurance, 2030 target: 100%) and injection safety (5% unsafe injections, 2030 target: 0%) had made substantial progress while harm reduction fell short (27 syringe and needle sets distributed per person who injects drugs per year, 2030 target: 300). Worldwide, 9% and 20% of the HBV- and HCV-infected population respectively, were aware of their status (2030 targets: 90%). In the short term, to reach the 2020 target of diagnosing 50% of those infected, 107 million HBV infected persons and 15 million HCV infected persons should be urgently diagnosed. Overall, in 2015, less than 10% of known infected persons were on HBV treatment or had started HCV treatment (2030 targets: 80%).

CONCLUSIONS

The prevention component of elimination is on track with respect to hepatitis B vaccination, blood safety, and injection safety. However, coverage of the hepatitis B vaccine timely birth dose requires a substantial increase, particularly in sub-Saharan Africa, and harm reduction needs to be taken to scale as injecting drug use accounts for a third of mortality from HCV infection. A promising but limited start in hepatitis testing and treatment needs to be followed by immediate and sustained action so that we reach the service coverage targets required to achieve elimination by 2030. Treating persons coinfected with HIV and hepatitis viruses is particularly urgent and needs to be promoted in the context of the HIV response.

Molecular evolution and phylodynamics of hepatitis B virus infection circulating in Iran

Previous local and national Iranian publications indicate that all Iranian hepatitis B virus (HBV) strains belong to HBV genotype D. The aim of this study was to analyze the evolutionary history of HBV infection in Iran for the first time, based on an intensive phylodynamic study. The evolutionary parameters, time to most recent common ancestor (tMRCA), and the population dynamics of infections were investigated using the Bayesian Monte Carlo Markov chain (BMCMC). The effective sample size (ESS) and sampling convergence were then monitored. After sampling from the posterior distribution of the nucleotide substitution rate and other evolutionary parameters, the point estimations (median) of these parameters were obtained. All Iranian HBV isolates were of genotype D, sub-type ayw2. The origin of HBV is regarded as having evolved first on the eastern border, before moving westward, where Isfahan province then hosted the virus. Afterwards, the virus moved to the south and west of the country. The tMRCA of HBV in Iran was estimated to be around 1894, with a 95% credible interval between the years 1701 and 1957. The effective number of infections increased exponentially from around 1925 to 1960. Conversely, from around 1992 onwards, the effective number of HBV infections has decreased at a very high rate. Phylodynamic inference clearly demonstrates a unique homogenous pattern of HBV genotype D compatible with a steady configuration of the decreased effective number of infections in the population in recent years, possibly due to the implementation of blood donation screening and vaccination programs. Adequate molecular epidemiology databases for HBV are crucial for infection prevention and treatment programs.

Lettuce-produced hepatitis C virus E1E2 heterodimer triggers immune responses in mice and antibody production after oral vaccination

The hepatitis C virus (HCV) is a major etiologic agent for severe liver diseases (e.g. cirrhosis, fibrosis and hepatocellular carcinoma). Approximately 140 million people have chronic HCV infections and about 500 000 die yearly from HCV-related liver pathologies. To date, there is no licensed vaccine available to prevent HCV infection and production of a HCV vaccine remains a major challenge. Here, we report the successful production of the HCV E1E2 heterodimer, an important vaccine candidate, in an edible crop (lettuce, Lactuca sativa) using Agrobacterium-mediated transient expression technology. The wild-type dimer (E1E2) and a variant without an N-glycosylation site in the E2 polypeptide (E1E2∆N6) were expressed, and appropriate N-glycosylation pattern and functionality of the E1E2 dimers were demonstrated. The humoral immune response induced by the HCV proteins was investigated in mice following oral administration of lettuce antigens with or without previous intramuscular prime with the mammalian HEK293T cell-expressed HCV dimer. Immunization by oral feeding only resulted in development of weak serum levels of anti-HCV IgM for both antigens; however, the E1E2∆N6 proteins produced higher amounts of secretory IgA, suggesting improved immunogenic properties of the N-glycosylation mutant. The mice group receiving the intramuscular injection followed by two oral boosts with the lettuce E1E2 dimer developed a systemic but also a mucosal immune response, as demonstrated by the presence of anti-HCV secretory IgA in faeces extracts. In summary, our study demonstrates the feasibility of producing complex viral antigens in lettuce, using plant transient expression technology, with great potential for future low-cost oral vaccine development.

Specific memory B cell response and participation of CD4+ central and effector memory T cells in mice immunized with liposome encapsulated recombinant NE protein based Hepatitis E vaccine candidate

BACKGROUND

Liposome encapsulated neutralizing epitope protein of Hepatitis E virus (HEV), rNEp, our Hepatitis E vaccine candidate, was shown to be immunogenic and safe in pregnant and non-pregnant mice and yielded sterilizing immunity in rhesus monkeys.

METHODS

The current study in Balb/c mice assessed the levels and persistence of anti-HEV IgG antibodies by ELISA, frequencies of B, memory B, T and memory T cells by flow cytometry and HEV-specific IgG secreting memory B cells by ELISPOT till 420days post immunization (PI) with 5?g rNEp encapsulated in liposome based adjuvant (2 doses, 4weeks apart). Mice immunized with a lower dose (1?g) were assessed only for anamnestic response post booster dose.

RESULTS

Vaccine candidate immunized mice (5?g dose) elicited strong anti-HEV IgG response that was estimated to persist for lifetime. At day 120 PI, frequency of memory B cells was higher in immunized mice than those receiving adjuvant alone. Anti-HEV IgG titers were lower in mice immunized with 1?g dose. A booster dose yielded a heightened antibody response in mice with both high (>800GMT, 5?g) and low (?100GMT, 1?g) anti-HEV IgG titers. At day 6th post booster dose, HEV-specific antibody secreting plasma cells (ASCs) were detected in 100% and 50% of mice with high and low anti-HEV IgG titers, respectively, whereas the frequencies of CD4⁺ central and effector memory T cells were high in mice with high anti-HEV IgG titers only.

CONCLUSIONS

Taken together, the vaccine candidate effectively generates persistent and anamnestic antibody response, elicits participation of CD4⁺ memory T cells and triggers memory B cells to differentiate into ASCs upon boosting. This approach of assessing the immunogenicity of vaccine candidate could be useful to explore the longevity of HEV-specific memory response in future HEV vaccine trials in human.

Viral hepatitis vaccination during pregnancy

Viral hepatitis is a serious global public health problem. It is also a common cause of jaundice and gestational complications in pregnant women. Moreover, infected mothers can transmit the virus to their fetus or neonate, which may increase disease burden and decrease quality of life. To date, commercial vaccines have been developed for hepatitis A, B, and E and are available to the general population. The Advisory Committee on Immunization Practices currently accepts emergency vaccination against hepatitis A and B during pregnancy due to benefits that overweight the potential risks. While there are limited data from trials with limited numbers of samples that suggest the efficacy or safety of hepatitis B and E vaccines in pregnant women, additional data are necessary to provide evidence of vaccination during pregnancy.

Henry K. Beecher and the Oversight of Research in Children

Henry K. Beecher was a pioneer of research ethics and a prominent whistleblower with regard to ethically problematic studies. Most of his work focused on research in adults, not children, but he did speculate about the implications of his ethical concerns for research in minors. This paper reviews Beecher's response to Krugman's studies of hepatitis at the Willowbrook State School and the debate that Beecher's article stimulated between Ramsey and McCormick. That debate shaped the terms that were used in current federal regulations for research in children. The paper then speculates about whether Beecher would have approved of our current regulatory system.

Antibodies Targeting Novel Neutralizing Epitopes of Hepatitis C Virus Glycoprotein Preclude Genotype 2 Virus Infection

Currently, there is no effective vaccine to prevent hepatitis C virus (HCV) infection, partly due to our insufficient understanding of the virus glycoprotein immunology. Most neutralizing antibodies (nAbs) were identified using glycoprotein immunogens, such as recombinant E1E2, HCV pseudoparticles or cell culture derived HCV. However, the fact that in the HCV acute infection phase, only a small proportion of patients are self-resolved accompanied with the emergence of nAbs, indicates the limited immunogenicity of glycoprotein itself to induce effective antibodies against a highly evolved virus. Secondly, in previous reports, the immunogen sequence was mostly the genotype of the 1a H77 strain. Rarely, other genotypes/subtypes have been studied, although theoretically one genotype/subtype immunogen is able to induce cross-genotype neutralizing antibodies. To overcome these drawbacks and find potential novel neutralizing epitopes, 57 overlapping peptides encompassing the full-length glycoprotein E1E2 of subtype 1b were synthesized to immunize BALB/c mice, and the neutralizing reactive of the induced antisera against HCVpp genotypes 1–6 was determined. We defined a domain comprising amino acids (aa) 192–221, 232–251, 262–281 and 292–331 of E1, and 421–543, 564–583, 594–618 and 634–673 of E2, as the neutralizing regions of HCV glycoprotein. Peptides PUHI26 (aa 444–463) and PUHI45 (aa 604–618)-induced antisera displayed the most potent broad neutralizing reactive. Two monoclonal antibodies recognizing the PUHI26 and PUHI45 epitopes efficiently precluded genotype 2 viral (HCVcc JFH and J6 strains) infection, but they did not neutralize other genotypes. Our study mapped a neutralizing epitope region of HCV glycoprotein using a novel immunization strategy, and identified two monoclonal antibodies effective in preventing genotype 2 virus infection.

[Development of the novel oral vaccine against hepatitis C virus utilizing bifidobacteria]

Approximately 3% of the world people have chronically infected with hepatitis C virus (HCV), and about 30% of those will develop progressive liver disease, such as cirrhosis and hepatocellular carcinoma. The current standard treatment for HCV of a combination of pegylated interferon-α with ribavirin and the development of new direct-acting antiviral agents, have dramatically improved the virus eradication rate. However those treatments have some toxicities and too expensive to be applied in developing countries, where have high HCV infection rates. Therefore there is a still great need to develop the novel vaccines, which can protect or treat HCV infection with the high efficacies and low adverse effects and costs. Currently we are developing the novel oral vaccine against HCV utilizing bifidobacteria.

[IL-35 level of peripheral blood is correlated with the immune response to hepatitis B vaccine]

OBJECTIVE

To investigate the relationship of IL-35 level in peripheral blood mononuclear cells (PBMCs) and immune response to hepatitis B vaccine and explore the factors influencing vaccine immune reaction.

METHODS

Our follow-up study enrolled 400 healthy volunteers who had received a standard course of immunization with hepatitis B vaccine. Chemiluminescence method was carried out to quantitatively detect hepatitis B virus surface antibody (HBsAb). PBMCs were isolated from 8 cases of non- or hypo-responders and 8 cases of moderate or hyper-responders, and the total RNA was extracted. Real-time quantitative PCR was performed to detect Epstein-Barr virus (EBV)-induced gene 3 (EBI3) and IL-12p35 mRNA levels. Finally, serum IL-35 level was compared using ELISA between 40 cases of non- or hypo-responders and 40 cases of moderate or hyper-responders randomly selected from the healthy volunteers to analyze the association with HBsAb level.

RESULTS

The levels of EBI3 and IL-12p35 mRNAs in PBMCs in moderate or hyper-responders were significantly higher than those in non- or hypo-responders, and the former was (12.73 ± 2.26) and (7.93 ± 1.06) folds the latter, respectively. The serum IL-35 level in moderate or hyper-responders [(111.50 ± 49.53) ng/L] was significantly higher than that in non-or hypo-responders [(15.01 ± 12.82) ng/L]; and IL-35 level was positively correlated with HBsAb level (r=0.84).

CONCLUSION

Peripheral blood IL-35 level was closely correlated with the immune response to hepatitis B vaccine and low IL-35 level might be one of possible reasons or mechanisms underlying non-response or hypo-response to hepatitis B vaccine immunization.

[Immunogenicity and heterologous protection in mice with a recombinant adenoviral-based vaccine carrying a hepatitis C virus truncated NS3 and core fusion protein]

To develop a safe and broad-spectrum effective hepatitis C virus (HCV) T cell vaccine,we constructed the recombinant adenovirus-based vaccine that carried the hepatitis C virus truncated NS3 and core fusion proteins. The expression of the fusion antigen was confirmed by in vitro immunofluorescence and western blotting assays. Our results indicated that this vaccine not only stimulated antigen-specific antibody responses,but also activated strong NS3-specific T cell immune responses. NS3-specific IFN-γ+ and TNF-α+ CD4+ T cell subsets were also detected by a intracellular cytokine secretion assay. In a surrogate challenge assay based on a recombinant heterologous HCV (JFH1,2a) vaccinia virus,the recombinant adenovirus-based vaccine was capable of eliciting effective levels of cross-protection. These findings have im- portant implications for the study of HCV immune protection and the future development of a novel vaccine.

Oral immunization with recombinant hepatitis E virus antigen displayed on the Lactococcus lactis surface enhances ORF2-specific mucosal and systemic immune responses in mice

Hepatitis E virus (HEV) as a recognized zoonotic pathogen has posed global burden on public health, which is exacerbated by lack of efficient vaccine. In this study, we constructed a recombinant (inaQ-ORF2 gene fusion) Lactococcus lactis (L. lactis) strain NZ3900 that expresses and displays the hepatitis E virus antigen ORF2 utilizing an ice uncleation protein-based anchor system. After oral vaccination of BALB/c mice, significantly higher levels of ORF2-specific mucosal IgA and serum IgG were detected and cellular immunity was also induced. These findings further support that L. lactis-based HEV antigen vaccines could be used for human and animal protection against infection.

Hepatitis C virus hypervariable region 1 variants presented on hepatitis B virus capsid-like particles induce cross-neutralizing antibodies

Hepatitis C virus (HCV) infection is still a serious global health burden. Despite improved therapeutic options, a preventative vaccine would be desirable especially in undeveloped countries. Traditionally, highly conserved epitopes are targets for antibody-based prophylactic vaccines. In HCV-infected patients, however, neutralizing antibodies are primarily directed against hypervariable region I (HVRI) in the envelope protein E2. HVRI is the most variable region of HCV, and this heterogeneity contributes to viral persistence and has thus far prevented the development of an effective HVRI-based vaccine. The primary goal of an antibody-based HCV vaccine should therefore be the induction of cross-reactive HVRI antibodies. In this study we approached this problem by presenting selected cross-reactive HVRI variants in a highly symmetric repeated array on capsid-like particles (CLPs). SplitCore CLPs, a novel particulate antigen presentation system derived from the HBV core protein, were used to deliberately manipulate the orientation of HVRI and therefore enable the presentation of conserved parts of HVRI. These HVRI-CLPs induced high titers of cross-reactive antibodies, including neutralizing antibodies. The combination of only four HVRI CLPs was sufficient to induce antibodies cross-reactive with 81 of 326 (24.8%) naturally occurring HVRI peptides. Most importantly, HVRI CLPs with AS03 as an adjuvant induced antibodies with a 10-fold increase in neutralizing capability. These antibodies were able to neutralize infectious HCVcc isolates and 4 of 19 (21%) patient-derived HCVpp isolates. Taken together, these results demonstrate that the induction of at least partially cross-neutralizing antibodies is possible. This approach might be useful for the development of a prophylactic HCV vaccine and should also be adaptable to other highly variable viruses.

Strong vaccine-induced CD8 T-cell responses have cytolytic function in a chimpanzee clearing HCV infection

A single correlate of effective vaccine protection against chronic HCV infection has yet to be defined. In this study, we analyzed T-cell responses in four chimpanzees, immunized with core-E1-E2-NS3 and subsequently infected with HCV1b. Viral clearance was observed in one animal, while the other three became chronically infected. In the animal that cleared infection, NS3-specific CD8 T-cell responses were observed to be more potent in terms of frequency and polyfunctionality of cytokine producing cells. Unique to this animal was the presence of killing-competent CD8 T-cells, specific for NS3_1258–1272, being presented by the chimpanzee MHC class I molecule Patr-A*03∶01, and a high affinity recognition of this epitope. In the animals that became chronically infected, T-cells were able to produce cytokines against the same peptide but no cytolysis could be detected. In conclusion, in the animal that was able to clear HCV infection not only cytokine production was observed but also cytolytic potential against specific MHC class I/peptide-combinations.

HCV-specific immune responses induced by CIGB-230 in combination with IFN-α plus ribavirin

AIM: To analyze hepatitis C virus (HCV)-specific immune responses in chronically infected patients under triple therapy with interferon-α (IFN-α) plus ribavirin and CIGB-230.

METHODS: CIGB-230 was administered in different schedules with respect to IFN-α plus ribavirin therapy. Paired serum and peripheral blood mononuclear cells (PBMC) samples from baseline and end of treatment were analyzed. The HCV-specific humoral response was tested by enzyme-linked immunosorbent assay, neutralizing antibodies were evaluated by cell culture HCV neutralization assays, PBMC proliferation was assayed by carboxyfluorescein succinimidyl ester staining and IFN-γ secretion was assessed by enzyme-linked immunospot. Data on virological and histological response and their association with immune variables are also provided.

RESULTS: From week 12 to week 48, all groups of patients showed a significant reduction in mean leukocyte counts. Statistically significant reductions in antibody titers were frequent, but only individuals immunized with CIGB-230 as early add-on treatment sustained the core-IgG response, and the neutralizing antibody response was enhanced only in patients receiving CIGB-230. Cell-mediated immune responses also tended to decline, but significant reductions in IFN-γ secretion and total absence of core-specific lymphoproliferation were exclusive of the control group. Only CIGB-230-immunized individuals showed de novo induced lymphoproliferative responses against the structural antigens. Importantly, it was demonstrated that the quality of the CIGB-230-induced immune response depended on the number of doses and timing of administration in relation to the antiviral therapy. Specifically, the administration of 6 doses of CIGB-230 as late add-on to therapy increased the neutralizing antibody activity and the de novo core-specific IFN-γ secretion, both of which were associated with the sustained virological response.

CONCLUSION: CIGB-230, combined with IFN-α-based therapy, modifies the immune response in chronic patients. The study provides evidence for the design of more effective therapeutic vaccine interventions against HCV.

Therapeutic DNA vaccination using in vivo electroporation followed by standard of care therapy in patients with genotype 1 chronic hepatitis C

Clearance of infections caused by the hepatitis C virus (HCV) correlates with HCV-specific T cell function. We therefore evaluated therapeutic vaccination in 12 patients with chronic HCV infection. Eight patients also underwent a subsequent standard-of-care (SOC) therapy with pegylated interferon (IFN) and ribavirin. The phase I/IIa clinical trial was performed in treatment naive HCV genotype 1 patients, receiving four monthly vaccinations in the deltoid muscles with 167, 500, or 1,500 μg codon-optimized HCV nonstructural (NS) 3/4A-expressing DNA vaccine delivered by in vivo electroporation (EP). Enrollment was done with 2 weeks interval between patients for safety reasons. Treatment was safe and well tolerated. The vaccinations significantly improved IFN-γ-producing responses to HCV NS3 during the first 6 weeks of therapy. Five patients experienced 2-10 weeks 0.6-2.4 log10 reduction in serum HCV RNA. Six out of eight patients starting SOC therapy within 1-30 months after the last vaccine dose were cured. This first-in-man therapeutic HCV DNA vaccine study with the vaccine delivered by in vivo EP shows transient effects in patients with chronic HCV genotype 1 infection. The interesting result noted after SOC therapy suggests that therapeutic vaccination can be explored in a combination with SOC treatment.

Fulminant viral hepatitis

Acute liver failure (ALF) is a condition wherein the previously healthy liver rapidly deteriorates, resulting in jaundice, encephalopathy, and coagulopathy. There are approximately 2000 cases per year of ALF in the United States. Viral causes (fulminant viral hepatitis [FVH]) are the predominant cause of ALF in developing countries. Given the ease of spread of viral hepatitis and the high morbidity and mortality associated with ALF, a systematic approach to the diagnosis and treatment of FVH is required. In this review, the authors describe the viral causes of ALF and review the intensive care unit management of patients with FVH.

Liposome-based HCV vaccine enhances protective cellular immunity and IFN-gamma secretion in mice

HCV is a worldwide health problem and with the lack of effective treatment, vaccination becomes an urgent task, especially in developing countries. The effective vaccine should elicit long-lasting antibodies but most importantly induce a vigorous, multi-specific cellular immune response that includes both helper and cytotoxic T lymphocytes. Advances in liposome technology account for much of the progress in vaccine delivery systems. Therefore, this study aimed at investigating the potential immunogenicity of HCV core antigen, and assessing the influence of the novel antigen carried on liposomes on T cell proliferation and IFN-gamma production as potent markers of cellular immune response. Several formulations for immunization were prepared, including liposomal encapsulation of the Ag. The study was conducted on a total of 95 female inbred (C57B1/6J) mice divided into five groups including a control group. Spleen lymphocytes were evaluated for cellular proliferation using 3-(4, 5-Dimethylthiazol-2-YI)-2, 5-Diphenyltetrazolium Bromide (MTT) assay and for secretion of IFN-gamma by ELISA. Mice injected with liposomes carrying HCV core Ag (group 1) showed a highly significant increase in splenocytes proliferation (spontaneously and after stimulation with the Ag) compared to all other groups, with a stimulation index (S.I) of 1.47 (P < 0.001). The second highest cellular proliferation was noticed in mice injected with core Ag and CFA (group 2) (S.I = 1.29) with a significant difference from group I (P = 0.001). Mice injected with core Ag alone showed a non-significant difference from the control group (P = 0.126). IFN-gamma level was the highest in liposomal Ag group with a highly significant difference; both spontaneously (56.3 pg/L) and with stimulation (68.32) (P < 0.001) followed by mice injected with core Ag with CFA. In conclusion, Liposomal formulation of HCV peptide vaccine is effective as direct in vivo antigen loading and activation of T cells leading to protective HCV antiviral responses.

The impact of new vaccine introduction on the coverage of existing vaccines: a cross-national, multivariable analysis

BACKGROUND

A surge of new and underutilized vaccine introductions into national immunization programmes has called into question the effect of new vaccine introduction on immunization and health systems. In particular, countries deciding whether to introduce a new or underutilized vaccine into their routine immunization programme may query possible effects on the delivery and coverage of existing vaccines. Using coverage of diphtheria-tetanus-pertussis (DTP) vaccine as a proxy for immunization system performance, this study aims to test whether new vaccine introduction into national immunization programs was associated with changes in coverage of three doses of DTP vaccine among infants.

METHODS AND FINDINGS

DTP3 vaccine coverage was analyzed in 187 countries during 1999-2009 using multivariable cross-national mixed-effect longitudinal models. Controlling for other possible determinants of DTP3 coverage at the national level these models found minimal association between the introduction of Hepatitis-, Haemophilus influenzae type b-, and rotavirus-containing vaccines and DTP3 coverage. Instead, frequent and sometimes large fluctuations in coverage are associated with other development and health systems variables, including the presence of armed conflict, coverage of antenatal care services, infant mortality, the percent of health expenditures that are private and total health expenditures per capita.

CONCLUSIONS

Introductions of new vaccines did not affect national coverage of DTP3 vaccine in the countries studied. Introductions of other new vaccines and multiple vaccine introductions should be monitored for immunization and health systems impacts.

In this issue of the International Reviews of Immunology

This issue hosts diverse topics, from myeloid derived suppressor cells (MDSC) with their mechanism and role in cancer, the interplay between diet and emerging allergies studied in a genetically closed population, the pleiotropic anti-inflammatory effects of resveratrol, to the quest to achieve more reliable immune correlates of protection against the hepatitis C virus (HCV).

Where are we in the justification of research involving chimpanzees?

On December 15, 2011, the Institute of Medicine (IOM) Committee on the Use of Chimpanzees in Biomedical and Behavioral Research issued a final report commissioned by the National Institutes of Health (NIH). It changed the landscape of discussion about the necessity of using chimpanzees in research. The Committee advanced three principles of scientifically warranted research on chimpanzees, but NIH's statement of task provided inadequate opportunity for the Committee to investigate moral problems and their implications for public policy. The IOM Committee's report is a landmark document, but it has weaknesses in its justificatory framework, largely resulting from the Committee's narrow remit from NIH and IOM. We analyze cases mentioned in the report and argue that numerous central ethical issues are neglected, especially ones of justification. Additionally, we consider whether the principles offered by the Committee could be used as criteria governing the use of other animals in biomedical and behavioral research.

Human broadly neutralizing antibodies to the envelope glycoprotein complex of hepatitis C virus

Hepatitis C virus (HCV) infects ∼2% of the world's population. It is estimated that there are more than 500,000 new infections annually in Egypt, the country with the highest HCV prevalence. An effective vaccine would help control this expanding global health burden. HCV is highly variable, and an effective vaccine should target conserved T- and B-cell epitopes of the virus. Conserved B-cell epitopes overlapping the CD81 receptor-binding site (CD81bs) on the E2 viral envelope glycoprotein have been reported previously and provide promising vaccine targets. In this study, we isolated 73 human mAbs recognizing five distinct antigenic regions on the virus envelope glycoprotein complex E1E2 from an HCV-immune phage-display antibody library by using an exhaustive-panning strategy. Many of these mAbs were broadly neutralizing. In particular, the mAb AR4A, recognizing a discontinuous epitope outside the CD81bs on the E1E2 complex, has an exceptionally broad neutralizing activity toward diverse HCV genotypes and protects against heterologous HCV challenge in a small animal model. The mAb panel will be useful for the design and development of vaccine candidates to elicit broadly neutralizing antibodies to HCV.

Sharp injuries among hospital waste handlers

BACKGROUND

Health care workers are generally predisposed to injuries from sharps as a health hazard. This is more pronounced among waste handlers.

OBJECTIVE

It is therefore important to assess these injuries among this group of people with a view to identifying the risk factors and suggesting preventive methods.

METHODS

Questionnaires were administered to People handling wastes in our hospital to assess their level of education on injury prevention, immunization status and preventive methods used by them to prevent these injuries and subsequent infections.

RESULTS

Forty three waste handlers were interviewed. Twenty eight (65.8%) of them received training before commencing on the job while 14 (32.5%) never received any training. Only thirty nine (90.7%) of them always use hand gloves before carrying wastes. Only three (7.0%) of the respondents have been screened for Hepatitis B, 19 (44.2%) for HIV, while 10 (23.3%) were screened for Hepatitis B, C, and HIV. Eleven (25.6%) of them have been injured with sharps. The finger was the most injured in 7 (93%) of them.

CONCLUSION

Training and re-training of health workers is important and should be encouraged. All health workers should have pre-employment immunization against Hepatitis B, C as well as other before commencing on their jobs. Workers should be screened for infective diseases that can be of legal problem while at the job and the workers should be effectively immunized.

HIV risk, prevention, and testing behaviors among men who have sex with men--National HIV Behavioral Surveillance System, 21 U.S. cities, United States, 2008

PROBLEM/CONDITION

Approximately 1.1 million persons in the United States are living with human immunodeficiency virus (HIV) infection. More than half of those infected are men who have sex with men (MSM).

REPORTING PERIOD

June-December 2008.

DESCRIPTION OF SYSTEM

The National HIV Behavioral Surveillance (NHBS) System collects risk behavior data from three populations at high risk for HIV infection: MSM, injection-drug users, and heterosexual adults at increased risk for HIV infection. Data for NHBS are collected in rotating cycles. NHBS participants must be aged ≥18 years, live in a participating metropolitan statistical area, and be able to complete a behavioral survey in English or Spanish. Men who reported being infected with HIV or who had no male sex partners during the past 12 months were excluded from this analysis.

RESULTS

This report summarizes data gathered from 8,175 MSM during the second data collection cycle of NHBS. In addition to having at least one male sex partner, 14% of participants had at least one female sex partner during the past 12 months. Unprotected anal intercourse with a male partner was reported by 54% of the participants; 37% reported having unprotected anal sex with a main male partner (someone with whom the participant had sex and to whom he felt most committed, such as a boyfriend, spouse, significant other, or life partner), and 25% reported having unprotected anal sex with a casual male partner (someone with whom the participant had sex but with whom he did not feel committed, did not know very well, or had sex with in exchange for something such as money or drugs). Noninjection drug use during the past 12 months was reported by 46% of participants. Specifically, 38% used marijuana, 18% cocaine, 13% poppers (amyl nitrate), and 11% ecstasy. Two percent of the participants reported injecting drugs for nonmedical purposes in the past 12 months. Of the participants surveyed, 90% had been tested for HIV during their lifetime, 62% had been tested during the past 12 months, 51% had received a hepatitis vaccination, 35% had been tested for syphilis during the past 12 months, and 18% had participated in an individual- or group-level HIV behavioral intervention.

INTERPRETATION

MSM in the United States continue to engage in sexual and drug-use behaviors that increase the risk for HIV infection. Although many MSM had been tested for HIV infection, many had not received hepatitis vaccinations or syphilis testing, and only a small proportion had recently participated in a behavioral intervention.

PUBLIC HEALTH ACTION

To reduce HIV infection among MSM, additional effort is needed to decrease the number of men who are engaging in risk behaviors while increasing the number who recently have been tested for HIV. The National HIV/AIDS Strategy for the United States delineates a coordinated response to reduce infections and HIV-related health disparities among MSM and other disproportionately affected groups. NHBS data can be used to monitor progress toward the goals of the national strategy and to guide national and local planning efforts to maximize the impact of HIV prevention programs.

Clearance of genotype 1b hepatitis C virus in chimpanzees in the presence of vaccine-induced E1-neutralizing antibodies

Accumulating evidence indicates that neutralizing antibodies play an important role in protection from chronic hepatitis C virus (HCV) infection. Efforts to elicit such responses by immunization with intact heterodimeric E1E2 envelope proteins have met with limited success. To determine whether antigenic sites, which are not exposed by the combined E1E2 heterodimer structure, are capable of eliciting neutralizing antibody responses, we expressed and purified each as separate recombinant proteins E1 and E2, from which the immunodominant hypervariable region (HVR-1) was deleted. Immunization of chimpanzees with either E1 or E2 alone induced antigen-specific T-helper cytokines of similar magnitude. Unexpectedly, the capacity to neutralize HCV was observed in E1 but not in animals immunized with E2 devoid of HVR-1. Furthermore, in vivo only E1-vaccinated animals exposed to the heterologous HCV-1b inoculum cleared HCV infection.

[Viral markers of hepatitis B, C and D and HB vaccination status of a health care team in a rural district of Cameroon]

Ninety-three health care workers (HCW) in the Tokombere sahelian district volunteered to participate in a trial to investigate viral markers of hepatitis B, C, and D and HB vaccination status.

METHODS

. Sera were tested using the Vikia HBsAg kit followed by CMIA for detection of HBsAg, anti-HBs, anti-HBc, and anti-HCV. HBsAg-positive HCW were tested for HBV-DNA, anti-HDV, and, if positive for anti-HDV, HDV-RNA.

RESULTS

Analysis of anti-HBc positivity indicated that 91% of HCW had been infected by HBV, regardless of vaccination history. Vikia HBsAg results were confirmed by chemiluminescent microparticle immunoassay (CMIA) in all HCW and were positive in 17 HCW with virus load >2000 IU/mL in 6 and HDV co-infection in 6. Anti-HCV was found in 6 HCW. Among the 55 HCW that had not been vaccinated, only 3 needed vaccination because of anti-HBc negativity. Among HCW considered for HBV treatment, one patient presenting HBV/HDV co-infection was excluded after diagnosis of hepatocarcinoma.

CONCLUSION

Systematic HB vaccination of new HCW appears unnecessary in this rural region of Africa. Anti-HBc screening is cost-effective for identifying HCW requiring vaccination. Vikia HBsAg is effective for point-of-care screening. We underline the need for universal early (preferably neonatal) HB vaccination and for availability of anti-HBV drug in limited-resource countries.

[Prevention of virus hepatitis A to E]

Infection with hepatitis viruses can lead to acute hepatitis with the risk of developing liver failure. Chronic viral hepatitis may evolve into liver cirrhosis and hepatocellular carcinoma. Thus, prevention of viral hepatitis and its sequels is essential. Vaccination against hepatitis A is successful in almost all individuals. Protective antibodies maintain for at least 20 years. Booster vaccinations are not necessary. Since the introduction of hepatitis A vaccines, the incidence of new HAV-infections has declined significantly. Hepatitis B vaccines are safe and highly effective. Special populations such as dialysis patients or immunocompromised patients require special vaccine schedules. New vaccines with improved adjuvants are currently being tested in clinical trials. So far there is no hepatitis C vaccine on the horizon. Prophylaxis of HCV-infections relies primarily on hygiene measures. Early therapy of acute hepatitis C can prevent chronic hepatitis C. HDV-infection can only be established if HBsAg is present. Thus, prevention of hepatitis B or elimination of HBsAg means prevention of hepatitis delta. Hepatitis E vaccines have been evaluated in phase III studies. The development of HEV vaccines becomes more relevant since chronic HEV infections have been reported in immunosuppressed individuals.

Murine neutralizing antibody response and toxicity to synthetic peptides derived from E1 and E2 proteins of hepatitis C virus

INTRODUCTION

The highest estimated prevalence of HCV infection has been reported in Egypt, nearly 12% mostly type 4. Currently, a commercial vaccine to protect this high risk population as well as global HCV infected patients is not available.

OBJECTIVES

In the present study, we aim at: (1) examining the viral binding capacities of purified monospecific polyclonal murine antibodies raised against genetically conserved viral protein sequences, i.e. synthetic peptides derived from those sequences located within envelope proteins and (2) assessment of immunogenic properties and safety parameters of those peptides individually and in a vaccine format in mice.

METHODS

Purified IgG Abs from immunized mice were used in immunocapture RT-PCR experiments to test viral neutralization by Abs raised against each of 4 peptides termed p35 (E1), p36 (E2), p37 (E2) and p38 (E2). Swiss mice were immunized with each of the 3 peptides (p35, p37 and p38) which generated neutralizing antibodies in immunocapture experiments. Antibody responses to corresponding peptides were determined using different routes of administration, different adjuvants, different doses and at different time points post-injection. To explore the dose range for future pharmacological studies, three doses namely 50 ng, 10 μg and 50 μg/25 gm mouse body weight were tested for biochemical and histopathological changes in several organs.

RESULTS

Murine Abs against p35, p37 and p38 but not p36 showed HCV neutralization in immunocapture experiments. Subcutaneous injection of peptides elicited higher responses than i.m. and i.p. Immunization with Multiple Antigenic Peptide (MAP) form or coupled to Al PO4 elicited the highest Ab responses. Peptide doses of 50 ng/25 gm body weight or less were effective and safe, however dose assessment still requires further study. Histopathological changes were observed in animals that received doses ∼1000 times higher than the potential therapeutic dose.

CONCLUSION

Exploration of humoral immunogenicity, neutralization capacity and safety suggested that the peptides presented herein are candidate vaccine components for further preclinical assessment.

Efficacy and safety of a recombinant hepatitis E vaccine in healthy adults: a large-scale, randomised, double-blind placebo-controlled, phase 3 trial

BACKGROUND

Seroprevalence data suggest that a third of the world's population has been infected with the hepatitis E virus. Our aim was to assess efficacy and safety of a recombinant hepatitis E vaccine, HEV 239 (Hecolin; Xiamen Innovax Biotech, Xiamen, China) in a randomised, double-blind, placebo-controlled, phase 3 trial.

METHODS

Healthy adults aged 16-65 years in, Jiangsu Province, China were randomly assigned in a 1:1 ratio to receive three doses of HEV 239 (30 microg of purified recombinant hepatitis E antigen adsorbed to 0.8 mg aluminium hydroxide suspended in 0.5 mL buffered saline) or placebo (hepatitis B vaccine) given intramuscularly at 0, 1, and 6 months. Randomisation was done by computer-generated permuted blocks and stratified by age and sex. Participants were followed up for 19 months. The primary endpoint was prevention of hepatitis E during 12 months from the 31st day after the third dose. Analysis was based on participants who received all three doses per protocol. Study participants, care givers, and investigators were all masked to group and vaccine assignments. This trial is registered with ClinicalTrials.gov, number NCT01014845.

FINDINGS

11,165 of the trial participants were tested for hepatitis E virus IgG, of which 5285 (47%) were seropositive for hepatitis E virus. Participants were randomly assigned to vaccine (n=56,302) or placebo (n=56,302). 48,693 (86%) participants in the vaccine group and 48,663 participants (86%) in the placebo group received three vaccine doses and were included in the primary efficacy analysis. During the 12 months after 30 days from receipt of the third dose 15 per-protocol participants in the placebo group developed hepatitis E compared with none in the vaccine group. Vaccine efficacy after three doses was 100.0% (95% CI 72.1-100.0). Adverse effects attributable to the vaccine were few and mild. No vaccination-related serious adverse event was noted.

INTERPRETATION

HEV 239 is well tolerated and effective in the prevention of hepatitis E in the general population in China, including both men and women age 16-65 years.

FUNDING

Chinese National High-tech R&D Programme (863 programme), Chinese National Key Technologies R&D Programme, Chinese National Science Fund for Distinguished Young Scholars, Fujian Provincial Department of Sciences and Technology, Xiamen Science and Technology Bureau, and Fujian Provincial Science Fund for Distinguished Young Scholars.

[Construction and evaluation of hepatitis C virus (HCV) DNA vaccine containing E2-gAD fusion gene]

OBJECTIVE

To rational design HCV DNA vaccine candidates and evaluate their specific We design to construct two DNA vaccine candidates, one consists of immunity to HCV in mice.

METHODS

We design to construct two DNA vaccine candidates, one consists of E2 (the envelope glycoprotein 2 of HCV) gene only, the second consists of E2-gAD (Globular Domain of Human Adiponectin) fusion gene via overlapping PCR. Confirm the expression of the DNA vaccines by Western blotting, and then vaccinated by injection of DNA vaccines with gene electrotransfer (GET) in BALB/c mice. The immune response was measured by IFN-gamma ELISPOT.

RESULTS

The DNA vaccine candidate consists of E2-gAD could effectively express in vitro , and it could induced a higher anti-HCV T cell response in mice than the one consists of E2 only.

CONCLUSION

The HCV DNA vaccine consists of E2-gAD fusion can increase the immunity of the E, to some extend, and the research paved a way to develop and optimize the novel HCV DNA vaccine.

[Hepatitis C in lodzkie voivodeship in 2003-2008]

HCV infection may result in serious health consequences such as chronic hepatitis C, liver cirrhosis and hepatocelulare carcinoma. In lodzkie voivodeship, the data from 2003- 2008 demonstrate a slight upward trend. In 2003 there were 280 registered cases (incidence 10.76 per 100 000). In the year 2008, a number of cases (199) and an incidence (7.8 per 100 000) of hepatitis C was lower than in prodecting years. Hepatitis C cases aged 15-19 constituted the most predominant group. As observed previously the incidence in the urban areas was two times higher than the incidence in rural areas and the incidence in men was twice higher than in women. In men the highest incidence was noted in the age group 15-19 and 20-24 years and in women in the age group 15-19 and 60-64 years in the urban areas and 15-19 and 20-24 in the rural areas. The increasing trend in incidence over the last six years may be explained by continuous improvement of diagnosis and notification.

What is on the horizon for treatment of chronic hepatitis C?

Current guidelines for chronic Hepatitis C recommend peginterferon-alpha and ribavirin combination therapy for 24 or 48 weeks, based on viral factors (genotype, viral load), host factors (stage of liver disease) and virological response during treatment. The main goal of treatment is eradication of Hepatitis C virus (HCV) infection which is defined by HCV RNA negativity 24 weeks after end of treatment (i.e. sustained virological response, SVR). SVR can be achieved in up to 80% of patients. Most patients, however, experience adverse events during therapy which significantly affect drug compliance and treatment outcome. Several strategies have been evaluated in order to optimize outcome of current peginterferon-based therapy, including higher dosing of peginterferon and/or ribavirin, and adjusting therapy duration. Although some patients might benefit from these optimized treatment schedules, viral eradication remains unachievable in a substantial part of patients. In this perspective, there is a clear need for effective alternative or additional agents, especially as the burden of disease is expected to increase over the next decade. Potential novel antiviral targets are now being identified due to improved understanding of the HCV life cycle. Specifically targeted antiviral therapy for Hepatitis C (STAT-C) is in clinical development and has already shown to increase SVR rate. At this moment, however, SVR can only be achieved when combining new molecules with peginterferon therapy. The role of ribavirin has been questioned, but available evidence suggests that ribavirin has significant impact on treatment outcome and should therefore remain part of antiviral therapy. More than a decade of interferon-based therapy and potential new agents will be reviewed.

Open-label trial of therapeutic immunization with oral V-5 Immunitor (V5) vaccine in patients with chronic hepatitis C

We evaluated whether V-5 Immunitor (V5)--tableted therapeutic bivalent vaccine comprising heat-inactivated HCV antigens from pooled blood of HBV- and HCV-infected donors - may produce clinical benefit through induction of oral tolerance and reduction of immune-mediated liver injury. Once daily dose of V5 was administered per os to 10 patients with chronic hepatitis C in an open-label study that lasted 1 month. Every patient who entered the study had elevated liver enzyme levels, which at the end of study have decreased in 100% of analyzed patients. The reduction was highly significant, from 157.7+/-73.4 to 49.9+/-43.8 U/L (P=0.0013) and 147.0+/-79.2 to 58.7+/-56.6 U/L (P=0.0132), for ALT and AST, respectively. The AST/ALT ratio has improved from 0.93 to 1.18 (P=0.00058) indicating the reversion of progression to cirrhosis. None of intent-to-treat patients who were anti-HCV antibody positive at study entry, became negative after 1 month on V5 (P=0.998). All patients, except one, reported complete recuperation from hepatitis C-associated clinical symptoms present at baseline (P=0.0016) with Mantel Haenszel's odds ratio 9.4 (P=0.0021) at 95% confidence interval: 2.7<OR<476.3. No adverse events were observed at any time. The favorable biochemical and clinical responses have been observed in a small number of individuals for a limited time period. Larger scale and longer studies are needed to confirm our preliminary observations suggesting that V5 is safe and effective means for immunotherapy of chronic hepatitis C.