Factors affecting effectiveness of vaccination against hepatitis B virus in hemodialysis patients

Hepatitis B virus(HBV)is a major global health problem.Despite the success of the general measures against blood transmitted infections in hemodialysis(HD)units,the prevalence of HBV infection among the HD patients is still high.Thus vaccination against HBV is indicating in this population.However,compared with the general population the seroprotection achieved in HD patients remains relatively low,at about 70%.In this review patient,HD procedure and vaccine-associated factors that affect the efficacy of HBV vaccination are analyzed.Also alternative routes of HBV vaccine administration as well as new and more immunogenic vaccine formulations are discussed.However,besides scientific progress,vigilance of HD physicians and staff regarding the general measures against the transmission of blood borne infections and the vaccination against HBV is also required for reducing the prevalence of this viral infection.

Hepatitis C virus in the new era:Perspectives in epidemiology,prevention,diagnostics and predictors of response to therapy

Despite the great successes achieved in the fields of virology and diagnostics,several difficulties affect improvements in hepatitis C virus(HCV)infection control and eradication in the new era.New HCV infections still occur,especially in some of the poorest regions of the world,where HCV is endemic and long-term sequelae have a growing economic and health burden.An HCV vaccine is still no available,despite years of researches and discoveries about the natural history of infection and host-virus interactions:several HCV vaccine candidates have been developed in the last years,targeting different HCV antigens or using alternative delivery systems,but viral variability and adaption ability constitute major challenges for vaccine development.Many new antiviral drugs for HCV therapy are in preclinical or early clinical development,but different limitations affect treatment validity.Treatment predictors are important tools,as they provide some guidance for the management of therapy in patients with chronic HCV infection:in particular,the role of host genomics in HCV infection outcomes in the new era of direct-acting antivirals may evolve for new therapeutic targets,representing a chance for modulated and personalized treatment management,when also very potent therapies will be available.In the present review we discuss the most recent data about HCV epidemiology,the new perspectives for the prevention of HCV infection and the most recent evidence regarding HCV diagnosis,therapy and predictors of response to it.

Testing for hepatitis B virus alone does not increase vaccine coverage in non-immunized persons

AIM To determine whether hepatitis B virus(HBV)-testing could serve as a gateway to vaccinate non-immunized individuals in a low-prevalent country.METHODS Non-immunized subjects participating in a multi-center, HBV-testing campaign in Paris, France were identified and contacted via telephone 3-9 mo after testing in order to determine vaccination status. Vaccination coverage was evaluated in per-protocol(for all respondents) and intent-to-treat analysis(assuming all non-responders did not vaccinate).RESULTS In total, 1215/4924(24.7%) enrolled subjects with complete HBV serology were identified as nonimmunized and eligible for analysis. There were 99/902 successfully contacted subjects who had initiated HBV vaccination after screening: per-protocol, 11.0%(95%CI: 9.0-13.2); intent-to-treat, 8.2%(95%CI: 6.7-9.8). In multivariable analysis, vaccination was more likely to be initiated in individuals originating from moderate or high HBV-endemic countries(P < 0.001), patients with limited healthcare coverage(P = 0.01) and men who have sex with men(P = 0.02). When asked about the reasons for not initiating HBV vaccination, the most frequent response was "will be vaccinated later"(33.4%), followed by "did not want to vaccinate"(29.8%), and "vaccination was not proposed by the physician"(21.5%). Sub-group analysis indicated a stark contrast in vaccination coverage across centers, ranging from 0%-56%.CONCLUSION HBV-vaccination after HBV screening was very low in this study, which appeared largely attributed to physician-patient motivation towards vaccination. Increased vaccination coverage might be achieved by emphasizing its need at the organizational level.

Sex bias in response to hepatitis B vaccination in end-stage renal disease patients:Meta-analysis

AIM： To systematically review the literature for studies investigating the potential effect of gender of dialysis patients on the immunogenicity of hepatitis B virus vaccines. METHODS： Literature searches were conducted by the MEDLINE and Google Scholar. The key words used included “hepatitis B （HB）”, “vaccine”, “dialysis”, “hemodialysis”, “sex”, “male” and “female”. Data of seroresponse to HB vaccine in clinical trials regarding sex of the recipients have been achieved and analyzed. Finally data from 19 clinical trials have been pooled and analyzed.RESULTS： Analysis of response to HB vaccination in our dialysis population showed males significantly res-pond less to hepatitis B vaccination （P = 0.002, Z = 3.08） with no significant heterogeneity detected [P = 0.766; heterogeneity χ2 = 14.30 （df = 19）; I2 = 0%]. A reanalysis of the pooled data was conducted regarding the dialysis mode to evaluate potential differential impact of sex on HB vaccine response. Hemodialysis was the only subgroup that showed a signifcant difference regarding dialysis mode in response to HB vaccination regarding sex （ P = 0.042, Z = 2.03）.CONCLUSION： This Meta-analysis showed significant effect for the sex of chronic kidney disease and dialysis patients on the immunogenicity of HB vaccine. This sex discrimination was most prominent among hemodialysis patients.

Elicitation of strong immune responses by a DNA vaccine expressing a secreted form of hepatitis C virus envelope protein E2 in murine and porcine animal models

AIM： To characterize the immunogenicity of a hepatitis C virus （HCV） E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS： A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS： Intradermal injection of E2 DNA vaccine induced strong Th1-1ike immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-1ike ones in piglets. CONCLUSION： A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations.

Seroepidemiology of hepatitis A virus in Kuwait

AIM: To fi nd the current seroepidemiology of hepatitis A virus (HAV) in Kuwait.METHODS: A total of 2851 Kuwaitis applying for new jobs were screened.RESULTS: HAV-positive cases were 28.8%; 59% were males and 41% were females. The highest prevalence was in the Ahmadi area. High prevalence was among the group of non-educated rather than educated parents. This is the fi rst study in Kuwait demonstrating the shifting epidemiology of HAV.CONCLUSION: This study reflects the need of the Kuwaiti population for an HAV vaccine.

Hepatitis elimination by 2030: Progress and challenges

Globally, over 300 million people are living with viral he-patitis with approximately 1.3 million deaths per year. In 2016, World Health Assembly adopted the Global Health Sector Strategy on viral hepatitis to eliminate hepatitis by 2030. Different World Health Organization member countries are working on hepatitis control strategies to achieve hepatitis elimination. So far, only 12 countries are on track to achieve hepatitis elimination targets. The aim of the study was to give an update about the progress and challenges to achieving hepatitis elimination by 2030. According to the latest data, 87% of infants had received the three doses of hepatitis B virus （HBV） vaccination in the frst year of their life and 46% of infants had received a timely birth dose of HBV vaccination.There is a strong need to improve blood and injection safety. Rates of hepatitis B and C diagnosis are very low and only 11% of hepatitis B and C cases are diagnosed. There is a dire need to speed up hepatitis diagnosis and find the missing millions of people living with viral hepatitis. Up to 2016, only 3 million hepatitis C cases have been treated. Pricing of hepatitis C virus drugs is also reduced in many countries. The major hurdle to ach-ieve hepatitis elimination is lack of finances to support hepatitis programs. None of the major global donors are committed to invest in the fght against hepatitis. It will be very diffcult for the low and middle-income countries to fund their hepatitis control program. Hepatitis elimination needs strong fnancial and political commitment, support from civil societies, and support from pharmaceutical and medical companies around the globe.

Hepatitis B virus S gene mutants in infants infected despite immunoprophylaxis

Objective To assess the correlation between hepatitis B virus (HBV) surface gene mutant infection and hepatitis B (HB) vaccination failure Methods Using sera from 106 infants who were born to HBV carrier mothers and failed in HB immunoprophylaxis, HBV S gene was amplified by PCR, transferred to nylon membranes for Southern blots, and then hybridized with oligonucleotide probes Eleven of non hybridizing samples were used for DNA sequencing Results 93 4% (99/106) of the samples were HBV DNA positive, and 30 3% (30/99) failed to hybridize with at least one of the four probes DNA sequencing confirmed that 10 of the 11 samples had an S gene mutation with amino acid (aa) change The identified mutants included nucleotide (nt) 546T→A(aa131N→T), nt531T→C (aa126I→T), nt491A→C (aa113T→P), nt491T→A (aa113S→T), nt533C→A (aa127P→T), nt581T→A (aa143S→T), nt636A→T (aa161Y→F), and nt679A→C (aa175L→F) The sequence in one mother infant pair was completely the same, with mutations at aa131 and aa161 Conclusions The prevalence of HBV surface mutants is about 30% in the children failing in HB vaccination HBV mutants can infect infants by maternal infant transmission

LONG-TERM IMMUNOGENICITY AND EFFICACY OF RECOMBINANT YEAST DERIVED HEPATITIS B VACCINE FOR INTERRUPTION OF MOTHER-INFANT TRANSMISSION OF HEPATITIS B VIRUS

Recombinant DNA Yeast-Derived Hepatitis B Vaccine (RYHB vaccine) is comparable to and can replace Plasma-Derived Hepatitis B Vaccine (PHB vaccine) for the prevention of mother-nfant transmission of hepatitis B virus (HBV), but the duration of immune efficacy of RYHB vaccine is not clear. This study indicates the long-term efficacy for the prevention of mother-infant transmission of HBV. One hundred and six neonates born to HBsAg-arrier mothers with HBeAg positive were randomly divided into two groups, one receiving 20 μg per dose of RYHB vaccine and the another receiving 20 μg per dose of PHB vaccine on the day of birth, at 1 month and at 6 months (three times). Physical examination and blood tests were performed for all infants at 6, 12, 24, 36, 48 and 60 months of age. The results showed that the protective efficacies at 6, 12, 24, 36, 48 and 60 months were 67%, 75%, 63%, 62%, 57% and 56%, respectively for the RYHB vaccine group and 58%, 76%, 51%, 41%, 24% and 18%, respectively for the PHB vaccine group. The protective efficacy was notably significant in the last two years. The study indicates that the duration of protective efficacy is over 5 years with RYHB vaccine, being longer than that of PHB vaccine. These recipients of RYHB vaccine showed no side effects, and the vaccine is regarded as safe and effective.

Immunomodulatory and Antiviral Therapy Improved Functional Cure Rate in CHB Patients with High HBsAg Level Experienced NA

Background and Aims:A functional cure,or hepatitis B virus(HBV)surface antigen(HBsAg)loss,is difficult to achieve in patients with hepatitis B virus e antigen(HBeAg)-positive chronic hepatitis B.The HBV vaccine and granulocyte-macrophage colony-stimulating factor(GM-CSF)have been reported to help reduce HBsAg levels and promote HBsAg loss.In this prospective randomized trial,we evaluated HBsAg loss in patients receiving pegylated interferon α2b(PEGIFN-α2b)and tenofovir disoproxil fumarate(TDF),with and without GM-CSF and HBV vaccination.Methods:A total of 287 patients with HBeAg positive chronic hepati-tis B and seroconversion after nucleot(s)ide analog treat-ment were assigned randomly to three treatment groups for 48 weeks,TDF alone(control),PEGIFN-α2b+TDF,and PEGIFN-α2b+TDF+GM-CSF+HBV vaccine.The prima-ry endpoints were the proportions of patients with HBsAg loss and seroconversion at 48 and 72 weeks.Resu/ts:The cumulative HBsAg loss rates in the control,PEGIFN-α2b+TDF,and PEGIFN-α2b+TDF+GM-CSF+HBV vaccine groups at week 48 were 0.0%,28.3%,and 41.1%,respec-tively.The cumulative HBsAg seroconversion rates in these groups at week 48 were 0.0%,21.7%,and 33.9%,respec-tively.Multivariate regression analysis showed that GM-CSF use plus HBV vaccination was significantly associated with HBsAg loss(p=0.017)and seroconversion(p=0.030).Con-clusions:In patients with HBeAg-positive chronic hepatitis B and seroconversion after nucleot(s)ide analog treatment,immunomodulatory/antiviral treatment regimens effective-ly improved HBsAg loss,and the regimen including GM-CSF and HBV vaccination was most effective.