Prevention Of Hepatitis B Virus Infection Research Articles

Undergraduate health science students' knowledge, attitudes, and practices about hepatitis B virus infection prevention at Addis Ababa university, Ethiopia: a cross-sectional study

Background: Hepatitis B (HB) is a serious liver-damaging infection that is caused by the HB virus (HBV). Healthcare professionals are especially susceptible to HB, a serious global public health concern. The aim of this study was to assess the undergraduate health science students’ knowledge, attitudes, and practices regarding the prevention of HBV infection. Methods: A cross-sectional study was conducted among third- and fourth-year health science students at the college of health sciences (CHS), Addis Ababa university (AAU) in Ethiopia. Self-administered structured questionnaire was used to collect the data. Chi square was used to examine the relationship between the outcome variables (mean knowledge, attitude, and practice) and a few socio-demographic factors (age, sex, and year of study). Statistical significance will be determined by p values less than 0.05. Results: Half of the study participants had adequate knowledge about the HBV. More than half (55%) of research participants were in favor of the HBV vaccination. The Chi square test was used to look at the association between the participants' mean knowledge score and specific socio-demographic characteristics. However, no significant association has been found with any of the selected socio-demographic variables. Conclusions: While undergraduate health science students generally demonstrate an acceptable level of knowledge and positive attitudes toward HBV infection prevention, there remain significant gaps in practice, particularly regarding vaccination uptake and adherence to standard precautions.

The Effectiveness and Sero-Immunity of Hepatitis B Vaccination in People Who Use Drugs: A Systematic Review and Meta-Analysis.

Hepatitis B virus (HBV) vaccination has been available for over four decades. However, a synthesis of the evidence regarding the effectiveness of this strategy on preventing hepatitis B infection in people who use drugs (PWUD) is lacking. A systematic search of the MEDLINE (via PubMed), SCOPUS, Web of Science, and Cochrane Library databases was conducted up to June 2024. Eight studies reported on the effectiveness of HBV vaccination, defined as a positive result for HBsAg or anti-Hbc in vaccinated versus non-vaccinated PWUD, with a pooled effect size of 52% (95% CI: 28.2-67.9) for HBsAg and 31.89% (95% CI: 14.8-45.5) for anti-Hbc. For sero-immunity, defined as the proportion of vaccinated PWUD with levels of anti-HBs ≥ 10 mIU/mL, we found that 66.2% (95% CI: 0.61-0.71; I2 = 94%) had protective levels of anti-HBs. The results of this meta-analysis indicate that the incidence of HBV infection is lower in vaccinated PWUD than in those who did not receive the vaccine. However, the effectiveness is lower than that observed in the general population. This highlights the need for a thorough review of the factors influencing the prevention of HBV infection in PWUD.

Hepatitis B Knowledge, Risk Perception, Behavioral Skills, and Infection Burden among Students and Staff at Victoria University, Kampala, Uganda

Background: The global efforts concertedly endorsed towards eliminating viral hepatitis as a public health challenge necessitate the provision of adequate and pertinent information related to hepatitis B virus (HBV) infectivity, which will help in tackling the lingering chronicity of HBV infection in developing countries. This study aimed to assess the burden of HBV infection and the underlying predictors of HBV infection risk among students and staff of Victoria University, Uganda. Methods: We captured data from 164 conveniently selected participants. Surface antigen for HBV (HBsAg) was detected using rapid tests. Analysis of variance (ANOVA), regression analysis, and chi- square tests were performed to ascertain the study hypotheses at a cut-off of (p<0.05). Results: The respondents’ mean age was 24.25 ± 25.64 years. Relatively half (56.1%) were males. Students (85.4%) were predominant. Regarding the burden of hepatitis B virus infection, HBsAg prevalence was 4.3%, observed among unmarried, first-year students, and residents of Central Uganda. Students’ year of study (χ2 = 10.323, p =<0.035) was significantly associated with HBsAg status. Furthermore, the respondents obtained mean scores of 3.45±4.10, 3.71±4.44, and 10.90±11.80 for knowledge, risk perception, and behavioral skills, respectively. Similarly, inadequate HBV-specific knowledge (F = 13.85, p<0.001), low risk perception (F = 13.22, p<0.001), and bad behavioral skills (F = 64.05, p<0.001) all predicted the risk of HBV infection. Conclusion: The findings affirm the lingering high endemicity of HBV infection in Uganda and imply an immediate need for targeted university-based hepatitis-B-related education and relevant vaccination policies such as mass vaccination in academic institutions to prevent HBV infection effectively in Uganda.

«ДОРОЖНАЯ КАРТА» БИОМАРКЕРОВ ПРИ ЕСТЕСТВЕННОМ ТЕЧЕНИИ HBV-ИНФЕКЦИИ

Background. Hepatitis B virus (HBV) causes both acute and chronic infection that can be asymptomatic or mild, occur as severe or fulminant hepatitis. Testing for HBV markers and establishing a diagnosis of hepatitis B are a key component affecting the epidemic process and allowing people with CHB to receive effective care to prevent or slow down progressive liver damage. Objective. To present a diagnostic «road map» of HBV biomarkers for doctors of various specialties involved in the diagnosis, treatment, screening and prevention of HBV infection. Material and methods. An electronic search was carried out on PubMed, UpToDate, Scopus, Web of Science, elibrary, CDC, ECDC, WHO/WHO using key words. In accordance with the specified search criteria and the purpose of the study; the titles, abstracts and full texts of scientific articles were studied, that is fully reflected in the list of references. Results. There have been provided a description of CHB natural history, its well-known diagnostic markers and new serological opportunities for medical monitoring, such as nuclear antigen (HBcrAg), pregenomic RNA (pgRNA) as well as quantitative determination of antibodies - qAnti-HBc. The diagnostic and prognostic effectiveness of “classical” and “new” biomarkers when used together opens up new opportunities for solving epidemiological or clinical problems. Conclusions. The unavailability of new tests in the form of commercial diagnostic kits complicates the use of some of them, at least that of HBcrAg, pgRNA, qAnti-HBc, which are on the “waiting list” for implementation.

HBV Vaccines: Advances and Development.

Hepatitis B virus (HBV) infection is a global public health problem that is closely related to liver cirrhosis and hepatocellular carcinoma (HCC). The prevalence of acute and chronic HBV infection, liver cirrhosis, and HCC has significantly decreased as a result of the introduction of universal HBV vaccination programs. The first hepatitis B vaccine approved was developed by purifying the hepatitis B surface antigen (HBsAg) from the plasma of asymptomatic HBsAg carriers. Subsequently, recombinant DNA technology led to the development of the recombinant hepatitis B vaccine. Although there are already several licensed vaccines available for HBV infection, continuous research is essential to develop even more effective vaccines. Prophylactic hepatitis B vaccination has been important in the prevention of hepatitis B because it has effectively produced protective immunity against hepatitis B viral infection. Prophylactic vaccines only need to provoke neutralizing antibodies directed against the HBV envelop proteins, whereas therapeutic vaccines are most likely needed to induce a comprehensive T cell response and thus, should include other HBV antigens, such as HBV core and polymerase. The existing vaccines have proven to be highly effective in preventing HBV infection, but ongoing research aims to improve their efficacy, duration of protection, and accessibility. The routine administration of the HBV vaccine is safe and well-tolerated worldwide. The purpose of this type of immunization is to trigger an immunological response in the host, which will halt HBV replication. The clinical efficacy and safety of the HBV vaccine are affected by a number of immunological and clinical factors. However, this success is now in jeopardy due to the breakthrough infections caused by HBV variants with mutations in the S gene, high viral loads, and virus-induced immunosuppression. In this review, we describe various types of available HBV vaccines, along with the recent progress in the ongoing battle to develop new vaccines against HBV.

Uptake of hepatitis B vaccination and associated factors among health sciences students, Mogadishu, Somalia.

Hepatitis B is a potentially fatal liver infection caused by the hepatitis B virus (HBV). It is a serious issue for global health. It considerably raises the risk of cirrhosis and liver cancer-related death and can result in chronic infection. The risk of infection is high among health sciences students due to the risk of occupational contact with fluids of infected patients and the risk of needle stick injury. The most effective way of preventing HBV infection is the vaccination of students prior to their posting to healthcare settings. There is no data available about HBV vaccination uptake among Health Sciences students in Somalia. Therefore, this study aimed to determine HBV vaccination uptake and associated factors toward HBV among health science students in Somalia. A cross-sectional study was undertaken among health sciences students from August to October 2022. Data were gathered using Kobo Toolbox using a standardized questionnaire with questions on characteristics, knowledge attitude, and HBV prevention practices. A total of 569 students were involved in the study. Stata version 15 was utilized for the analysis. Bivariate and multivariate logistic regression analysis, as well as descriptive statistics, were performed. In order to assess the existence and significance of the relationship between the outcome and risk factors, an adjusted odds ratio with a 95% confidence interval (CI) was used. Statistical significance was considered as a p-value ≤0.05. Of the 569 study participants, 33.4% (95%CI: 29.6-37.4) received a full dose of the HBV vaccine in this study. Participants had good HBV prevention knowledge, attitudes, and practices at 69.6, 37.96, and 50.6%, respectively. The lack of access and the high cost of the vaccine were the reasons for not taking the vaccine. Second-year [AOR: 0.22 (0.12-0.43)]. Positive attitude [AOR: 0.54 (0.31-0.93)], and good practice [AOR: 6.99 (3.62-13.5)]. The study indicated that 33.4% of health sciences students had received the required HBV vaccination doses, academic year, attitude, and practice were significantly associated with full-dose vaccination status. The unavailability of the vaccine and the high cost of vaccination were the most common reasons for not taking the vaccine. It is recommended that students receive vaccinations before beginning clinical rotations, and give instruction on infection prevention strategies and general precautions, particularly regarding HBV infection.

The transmission of hepatitis B virus (HBV) infection from mother-to-infant (MTI) and the susceptibility of offspring to hepatitis B under intrauterine exposure to HBsAg.

Hepatitis B virus (HBV) causes long-term injury to the liver in patients with chronic hepatitis B. It was reported that nearly half of this disease's cases now result from mother-to-infant (MTI) transmission. Therefore, intervention during this period of transmission of HBV could effectively prevent HBV infection in infants. This study employed bioinformatics methods to analyze the datasets of MTI hepatitis B transmission obtained from the Gene Expression Omnibus (GEO) database. Through this analysis, we extracted valuable information to identify genes exhibiting differential expression and uncover the associated signal pathways. Ultimately, our investigations into alterations in immune function shed light on the underlying mechanisms of MTI HBV transmission. There were 593 genes that were significantly differentially expressed (512 up-regulated genes and 81 down-regulated genes) in the offspring CD8+T cells with Hepatitis B surface antigen (HBsAg) intrauterine exposure. The pathways enriched for differentially expressed genes have been revealed. Furthermore, we performed a correlation analysis between differentially expressed genes and maternal hepatitis B inheritance via the weighted gene co-expression network analysis (WGCNA) and eventually found a high correlation between the cyan module and the shape. Among them, there were 166 genes in the cyan module, which were mainly enriched in the phosphatidylinositol signaling system, glycerolipid metabolism, and other types of O-Glycan biosynthesis. Therefore, we speculated that these signaling pathways and the genes within may be closely related to hepatitis B susceptibility and maternal hepatitis B inheritance. In this study, we showed that differentially expressed genes and signaling pathways may be valuable in preventing MTI transmission of HBV.

Assessing Knowledge, Attitudes, and Practices: Regarding Hepatitis B Infection and Vaccination Among Healthcare Professionals at AL-Salama Hospital, Ameria, Baghdad City: A Cross-Sectional Investigation Conducted in October-November 2022.

Hepatitis B Virus (HBV): A High-Risk Infection for Healthcare Workers (HCWs) , Healthcare workers (HCWs) are at an increased risk of contracting the highly dangerous hepatitis B virus (HBV) due to their frequent exposure to contaminated bodily fluids, particularly blood. Implementing precautionary measures such as personal safety protocols and vaccination can effectively prevent HBV infection. Objective: 1- Evaluation of Healthcare Professionals' Knowledge, Attitudes, and Practices (KAP) Regarding Hepatitis B Infection and Vaccination. 2- Evaluating Immunization Status of Healthcare Workers (HCWs) in Al-Salama-Ameria Hospital, Primary Care, and Specialist Dental Care Centers in Relation to Hepatitis B Virus (HBV). Materials and methods: In October and November 2022, a cross-sectional study was conducted at Al Salama Hospital (90 participants), primary care centers (44 participants), and specialist dental care centers (20 participants) in Ameria, Baghdad. A self-administered, structured questionnaire was used to collect information, including the knowledge, attitudes, and practices (KAP) of healthcare workers (HCWs) as well as their demographic details. The study data were analyzed using descriptive statistics, including frequencies, proportions, and percentages, with the assistance of Excel software. Verbal consent was obtained from each participant, and their identities were kept anonymous throughout the study. Results: Our research comprised a total of 154 healthcare workers (HCWs), consisting of 59 A medical facility comprised of 95 medical staff and 95 paramedical staff, possessing a collective wealth of knowledge. score among the participants was 68%, indicating a moderate level of knowledge. In terms of attitude, the overall score was 75%, indicating a positive attitude towards hepatitis B virus (HBV) infection and vaccination. However, the overall practice score was 58%, indicating a need for improvement in implementing preventive measures. Within the medical staff, a mere 15% had undergone HBV screening, while a significant 67% had successfully received the recommended three doses of vaccination. among the paramedical staff who had not been previously screened for HBV, only 37% had completed the three doses of vaccination. Conclusion: The findings of the study indicated that healthcare workers (HCWs) had a higher overall attitude score (75%) compared to their knowledge (68%) and practice (58%) scores. However, the rate of vaccination, particularly among paramedical staff, was low.

Knowledge, Perception and Prevention Practices of Hepatitis B virus infection among Health Workers in a Tertiary Health Institution, Southwest Nigeria

Objective: Hepatitis B virus (HBV) infection is a major global health concern, with over 2 billion people infected and an estimated 391 million individuals chronically infected. Nigeria has one of the highest burdens of HBV infection; with an estimated 11% prevalence despite the availability of a highly effective vaccine since 1982 and advances in diagnostics. The disease continues to be a significant health problem globally, particularly in Nigeria where health workers are at high risk of infection. This study aimed to assess the knowledge, perception and practice of HBV infection prevention among health workers at Olabisi Onabanjo University Teaching Hospital, a tertiary health facility in Southwest Nigeria. Methods This research was a descriptive cross-sectional study which was conducted among 348 health workers selected through a stratified random sampling method. Data were elicited using a self-administered semi-structured questionnaire and analysed using IBM SPSS version 20. Relevant descriptive statistics were calculated and the result presented in tables. Results: The mean age of the respondents was 32.41±0.32 years. The majority had good knowledge (64.7%), positive perception about their risk (89.5%) and good practice (72.1%) of HBV prevention. 52.1% had never taken HBV vaccine and 10.5% did not plan to get screened for HBV. Conclusion: There is a need for improved awareness and sensitization on the prevention of HBV infection especially immunization among health workers. Also, adherence to infection control measures should be given more priority among the health workers.

Cost-effectiveness of a 3-antigen versus single-antigen vaccine for the prevention of hepatitis B in adults in the United States.

The first 3-antigen hepatitis B vaccine was approved by the United States (US) Food and Drug Administration in November 2021 and was recommended by the Centers for Disease Control and Prevention in 2022. We estimated the cost-effectiveness of this 3-antigen vaccine (PreHevbrio™) relative to the single-antigen vaccine, Engerix-BTM, to prevent hepatitis B virus (HBV) infection among US adults. A cost-effectiveness model was developed using a combined decision-tree and Markov structure to follow 100,000 adults over their remaining lifetimes after vaccination with either the 3-antigen or single-antigen vaccine. Outcomes from societal and healthcare sector perspectives were calculated for adults aged 18-44, 45-64, and ≥65years; adults with diabetes; and adults with obesity. Seroprotection rates were obtained from the phase3, head-to-head PROTECT trial (NCT03393754). Incidence, vaccine costs, vaccine adherence rates, direct and indirect costs, utilities, transition probabilities, and mortality were obtained from published sources. Health outcomes and costs (2020USD) were discounted 3% annually and reported by vaccine and population. One-way sensitivity and scenario analyses were conducted. In the model, the 3-antigen vaccine led to fewer HBV infections, complications, and deaths compared with the single-antigen vaccine in all modeled populations due to higher rates and faster onset of seroprotection. Compared with the single-antigen vaccine, the 3-antigen vaccine had better health outcomes, more quality-adjusted life-years (QALYs), and lower costs in adults aged 18-64years, adults with diabetes, and adults with obesity (dominant strategy). For adults aged ≥65years, the 3-antigen vaccine was cost-effective compared with the single-antigen vaccine ($26,237/QALY gained) below common willingness-to-pay thresholds ($50,000-$100,000/QALY gained). In sensitivity analyses, results were sensitive to vaccine cost per dose, incidence, and age at vaccination. The recently approved 3-antigen vaccine is a cost-saving or cost-effective intervention for preventing HBV infection and addressing the long-standing burden of hepatitis B among US adults.

Assessment of the Knowledge of Hepatitis B Virus Infection in Primary Healthcare Centers in Abuja, Nigeria

Hepatitis B virus (HBV) infection affects the liver and can lead to potentially life-threatening acute or chronic disease. The population with high HBV infection prevalence of ≥ 8%, such as Nigeria, presents the highest risk of HBV transmission among health-workers. There is a need to disseminate knowledge of HBV infection and the risk of transmission to health-workers. In this baseline study, the team assessed the knowledge of HBV infection among health-workers in Primary Healthcare Centers (PHCs) in AMAC, Abuja. We conducted cross-sectional descriptive research that studied 168 randomly selected health-workers from 58 PHCs in AMAC, collected data with a pre-tested structured questionnaire, and analyzed it with SPSS version 21.0. The knowledge level of HBV symptoms and transmission ranged from 57.1% to 85.7%s and 84.5% to 91.7%, respectively. About 67% demonstrated good knowledge of HBV screening for pregnant women and 69% of Hepatitis B vaccination at birth. All the PHCs (100%) reported the unavailability of guidelines/protocols for HBV infection in pregnancy management and prevention. Furthermore, 51.2%, 53.7%, and 55.6% demonstrated poor knowledge of referral, PMTCT eligibility, and increased need for laboratory tests, respectively. Moreover, 60.2% showed poor awareness of treatment eligibility and 61.2% of choice of drug. Concluding, the respondents demonstrated good knowledge of HBV infection symptoms, transmission, screening for pregnant women, and vaccination schedules to prevent HBV infection. They showed a poor understanding of the referral of pregnant HBV seropositive women from the PHCs to secondary/tertiary hospitals, PMTCT, laboratory requirements for pregnant seropositive clients, and management of chronic HBV in pregnancy. Keywords: Abuja, Hepatitis B virus Infection, Health-workers, Knowledge, Primary healthcare centers.

Evolving considerations for choice of hepatitis B vaccine.

There is currently no known cure for hepatitis B virus (HBV) infection, and HBV remains a major public health burden in the United States. The US Department of Health and Human Services has established a Viral Hepatitis National Strategic Plan with the goal of eliminating HBV infection in the United States by the year 2030. This goal will be achieved by reducing the incidence of new HBV infections by 90% and mortality by 65%, with a main focus on prevention of HBV infection through vaccination. Currently, 4 HBV vaccines (excluding bivalent vaccines) are available in the United States for use in adults, including Heplisav-B, which was approved by the FDA in November 2017 for use in adults 18 years and older. All 4 HBV vaccines are equally recommended as options for the prevention of HBV infection by the Advisory Committee on Immunization Practices. This article provides an overview of emerging considerations based on CDC recommendations and new clinical data around HBV vaccines, as well as the potential of Heplisav-B in fulfilling unmet needs that currently exist in the HBV prevention landscape.

Disease Burden of Hepatitis B Infection and Section Vaccination Trends in Healthcare Workers: A Prospective Cohort Study

Introduction: Hepatitis B Virus (HBV) infection is an important occupational hazard for Healthcare Workers (HCWs), with an approximately four-fold increased risk of acquiring this infection compared to the normal population. The horizontal mode of transmission is the predominant mode among HCWs. Additionally, vaccination trends among HCWs have been disappointing, with paramedics reported to have a higher risk of HBV transmission and receiving HBV vaccination less often than doctors. Aim: To determine the burden of hepatitis B infection and vaccination trends among HCWs. Materials and Methods: This cross-sectional study was conducted at Pandit Bhagwat Dayal Sharma PGIMS, Rohtak Haryana, India, from March 2019 to January 2020, enrolling 250 HCWs. The study included 80 junior residents, 17 house surgeons, 123 nursing staff, 18 Laboratory Technicians (LTs), and 12 Operation Theatre Assistants (OTAs). The subjects were divided into two groups: medical workers (Group-1; House Surgeons and Junior Residents) and paramedical workers (Group-2; Nursing staff, LTs, OTAs). The sample size was calculated using Probability Proportion to Size (PPS) of HCWs. Descriptive statistics were performed. Results: None of the subjects tested positive for Hepatitis B surface Antigen (HBsAg) during the study period. A total of 196 (78.4%) subjects were vaccinated, while 54 (21.6%) subjects remained Non-Vaccinated (NV). Out of the 196 vaccinated subjects, 140 (71.4%) were Completely Vaccinated (CV), and 56 (28.6%) were Incompletely Vaccinated (IV). The vaccination rate was highest among junior residents (95%) and lowest among LTs and OTAs (50%). Among the 80 junior residents, 76 (95%) were vaccinated, and 4 (5%) were NV. Among the 123 nursing staff, 89 (72.3%) were vaccinated, and 34 (27.7%) were CV, 9 (50%) were NV and 3 were in category of IV. Among the 18 LTs, 6 (33.3%) were CV, and 9 (50%) were NV. None of the 12 OTAs were CV, with 6 (50%) being NV. Conclusion: HCWs are at a potential risk of contracting HBV infection as an occupational hazard. There is need to strengthen efforts towards vaccination and prevention of HBV infection.

Occult Hepatitis B Infection in Kidney Transplant Patients

Occult hepatitis B infection (OBI) is still a topic of debate worldwide. It is defined as the presence of hepatitis B virus (HBV) DNA in serum and/or liver from HBsAg-negative subjects. OBI may lead to the development of cirrhosis and hepatocellular carcinoma. It continues to present several unique challenges in organ transplantation despite the availability of an effective vaccine to prevent HBV infection and the introduction of oral therapy to treat HBV infection. HBV reactivation following organ transplantation can occur even in recipients with absent hepatitis B surface antigen and remains an important cause of morbidity and mortality. Concerning OBI complications, the screening of HBV DNA by the highly sensitive molecular means should be implemented for both recipients of organ transplant and organ transplant donors especially in highly endemic areas of HBV. In the era of potent antivirals and with evolving knowledge, HBsAg (+) renal transplant candidates and recipients can be monitored and successfully treated. Kidney organs from HBsAg-negative and anti-HBc–positive donors should be considered for transplant candidates after weighing the risk-benefit ratio. All transplant candidates should receive HBV vaccination if they are not immune to facilitate receipt of an organ from a donor with anti-HBc seropositivity.

An ultralong-acting tenofovir ProTide nanoformulation achieves monthslong HBV suppression.

Treatment of chronic hepatitis B virus (HBV) requires lifelong daily therapy. However, suboptimal adherence to the existing daily therapy has led to the need for ultralong-acting antivirals. A lipophilic and hydrophobic ProTide was made by replacing the alanyl isopropyl ester present in tenofovir alafenamide (TAF) with a docosyl phenyl alanyl ester, now referred to as M1TFV. NM1TFV and nanoformulated TAF (NTAF) nanocrystals were formulated by high-pressure homogenization. A single intramuscular injection of NM1TFV, but not NTAF, delivered at a dose of TFV equivalents (168 milligrams per kilogram) demonstrated monthslong antiviral activities in both HBV-transgenic and human hepatocyte transplanted TK-NOG mice. The suppression of HBV DNA in blood was maintained for 3 months. Laboratory experiments on HBV-transfected HepG2.2.15 cells affirmed the animal results and the critical role of docosanol in the sustained NM1TFV antiviral responses. These results provide clear "proof of concept" toward an emerging therapeutic paradigm for the treatment and prevention of HBV infection.

Specific Binding and Endocytosis of Liposomes to HEK293T Cells via Myrisoylated Pre-S1 Peptide Bound to Sodium Taurocholate Cotransporting Polypeptide.

(1) Background: Sodium taurocholate cotransporting polypeptide (NTCP) functions as a key receptor for the hepatitis B virus (HBV) infection. Analyzing HBV and NTCP interaction is an important issue not only for basic research but also for the development of anti-HBV therapeutics. We developed here a novel model system to analyze the interaction of NTCP with liposomes instead of HBV. (2) Methods: Liposomal binding and endocytosis through NTCP in HEK293T cells were achieved by serial treatments of HEL293T cells transiently expressing NTCP-green fluorescence protein (GFP) fusion protein with a synthetic biotinylated pre-S1 peptide (Myr47-Bio) and streptavidin (SA) complex (i.e., Myr47-Bio+SA) followed by biotinylated liposomes. By this procedure, binding of [biotinylated liposomes]-[Myr47-Bio+SA]-[NTCP-GFP] was formed. (3) Results: Using this model system, we found that liposomal binding to NTCP on the cell surface via Myr47-Bio+SA was far more efficient than that to scavenger receptor class B type 1 (SR-B1). Furthermore, liposomes bound to cell surface NTCP via Myr47-Bio+SA were endocytosed into cells after cells were cultured at 37 °C. However, this endocytosis was suppressed by 4 °C or cytochalasin B treatment. (4) Conclusions: This model system will be useful for not only analyzing HBV entry mechanisms but also screening substances to prevent HBV infection.

Neutralization of hepatitis B virus with vaccine-escape mutations by hepatitis B vaccine with large-HBs antigen

Although the current hepatitis B (HB) vaccine comprising small-HBs antigen (Ag) is potent and safe, attenuated prophylaxis against hepatitis B virus (HBV) with vaccine-escape mutations (VEMs) has been reported. We investigate an HB vaccine consisting of large-HBsAg that overcomes the shortcomings of the current HB vaccine. Yeast-derived large-HBsAg is immunized into rhesus macaques, and the neutralizing activities of the induced antibodies are compared with those of the current HB vaccine. Although the antibodies induced by the current HB vaccine cannot prevent HBV infection with VEMs, the large-HBsAg vaccine-induced antibodies neutralize those infections. The HBV genotypes that exhibited attenuated neutralization via these vaccines are different. Here, we show that the HB vaccine consisting of large-HBsAg is useful to compensate for the shortcomings of the current HB vaccine. The combined use of these HB vaccines may induce antibodies that can neutralize HBV strains with VEMs or multiple HBV genotypes.

Insights into induction of the immune response by the hepatitis B vaccine.

After more than four decades of hepatitis B virus (HBV) vaccine implementation, its safety and efficacy in preventing HBV infection have been proven and several milestones have been achieved. Most countries have included HBV immunization schedules in their health policies and progress has been made regarding universalization of the first HBV vaccine dose at birth. All of these actions have significantly contributed to reducing both the incidence of HBV infection and its related complications. However, there are still many drawbacks to overcome. The main concerns are the deficient coverage rate of the dose at birth and the large adult population that has not been reached timely by universal immunization. Additionally, the current most widely used second-generation vaccines do not induce protective immunity in 5% to 10% of the population, particularly in people over 40-years-old, obese (body mass index > 25 kg/m2), heavy smokers, and patients undergoing dialysis or infection with human immunodeficiency virus. Recently developed and approved novel vaccine formulations using more potent adjuvants or multiple antigens have shown better performance, particularly in difficult settings. These advances re-launch the expectations of achieving the World Health Organization’s objective of completing hepatitis control by 2030.

Establishment of a human cell line with a surface display system for screening and optimizing Na+-taurocholate cotransporting polypeptide-binding peptides.

One of the most desirable targets for HBV medications is the sodium taurocholate cotransporting polypeptide (NTCP), an entry receptor for the hepatitis B virus (HBV). N-myristoylated preS1 2–48 (Myrcludex B or Hepcludex), an NTCP-binding peptide from the large surface protein of HBV, has been developed as the first-in-class entry inhibitor. However, its relatively large molecular weight contributes to increased immunogenicity and antibody production. As a result, it is preferable to look for an NTCP-binding peptide with a smaller size. To do this, we developed a human cell surface display strategy and screened peptides based on preS1-21. PreS1-21 (genotype D) was extended by 7 random amino acids and fused with mCherry and FasL transmembrane domain. The pooled constructs were transfected into HEK293 cells by using the transposon/transposase system to create a library displaying various peptides on the cell surface with red fluorescence. On the other hand, we expressed NTCP protein fused with EGFP on HEK293 and used the membrane lysate containing NTCP-GFP as the bait protein to select peptides with increased NTCP affinity. After 7 cycles of selection, the deep sequencing results revealed that some polypeptides were more than 1,000 times enriched. Further screening of the mostly enriched 10 peptides yields the peptide preS1-21-pep3. Replacing the preS1-21 sequence of preS1-21-pep3 with those from different genotypes demonstrated that the consensus sequence of genotype A–F had the best performance. The peptide (Myr-preS1-21-pep3) was synthesized and tested on the HepG2-NTCP cell model. The results showed that Myr-preS1-21-pep3 is approximately 10 times more potent than the initial peptide Myr-preS1-21 in preventing HBV infection. In conclusion, we developed a new strategy for screening peptides binding to membrane proteins and identified a new NTCP-binding peptide with a much smaller size than Hepcludex.

KNOWLEDGE, ATTITUDE AND PRACTICE OF DENTAL STUDENTS TOWARDS HEPATITIS B INFECTION IN ADEN UNIVERSITY, YEMEN

Hepatitis B virus (HBV) infection is a major worldwide public health issue. The risk of exposure to HBV among healthcare workers (HCWs) is a major concern, especially among students in health professions. This is a cross-sectional survey, aimed to assess the knowledge, attitude, and practices toward HBV infection among dental students, using an administered questionnaire containing 2 sections. The first section for demographic characteristics and the second section contained 15 questions on knowledge of HBV (7 questions), attitude (3 questions), and practices (5 Questions) of HBV infection. Dental students in the third, fourth, and fifth years of Aden University were included in the study. Descriptive statistics like frequencies and proportions were used to summarize the data. A total of 308 dental students participated in the study. Of these, 50.3% were males and 49.7% were females.A total of 77.2% of the students knew about the transmission and prevention of HBV infection. More than 75.0% of participants had a positive attitude towards preventive measures against HBV infection, and 78.2% of participants agreed that the HBV vaccine can prevent HBV infection. Only 0.97% of students were vaccinated against HBV infection and 53.9% of students knew about the postexposure treatment against HBV infection. The overall knowledge regarding HBV infection was found to be adequate among dental students. Dental students are at high risk of exposure to HBV infection owing to the low HBV vaccination rate. Therefore, dental students should be vaccinated prior to their entry into professional practices.