Recombinant Hepatitis B Virus Vaccine Research Articles

Outcome of Infants Born to Women with Chronic Hepatitis B: A Local Risk-Based Strategy in a Low Prevalence Country.

Chronic hepatitis-B virus (HBV) infection due to mother-to-child transmission (MTCT) during the perinatal period is an important global health concern. Chile is a low-prevalence country with an increasing migratory inflow from Latin- American countries, with intermediate to high endemic rates of HBV infection, and until 2021, there is no universal maternal screening. This study aimed to evaluate infant outcomes using a risk-based strategy of maternal screening to prevent MTCT of hepatitis B virus (HBV) in a low-prevalence country. This prospective study included infants born to HBsAg-positive women detected using a local risk-based strategy. The exposed infants received immunoprophylaxis (IP) and follow-up to evaluate their clinical outcomes and immune responses through post-serological vaccine testing (PSVT) after completing the three- dose schedule of the HBV vaccine. A total of 99 HBsAg-positive mothers were detected. Seventy-six (82%) infants completed the follow-up and had PSVT between 9 and 12 months of age. 55.2% female, the median gestational age was 39 weeks (25-41) and the median birth weight was 3,130g (816-4,400 g). All patients received IP with recombinant HBV vaccine plus hepatitis-B virus immunoglobulin (HBIG) and three doses of the HBV vaccine. There were no cases of HBV infection, and 96% (72) responded to immunization with HBsAg antibodies (anti-HBsAg) >10 UI/ml, with a median level of 799 IU/ml. A high-risk strategy can be implemented in countries with non-universal screening for VHB. Timely IP plus high-uptake VHB vaccination in infants born to HBsAg-positive mothers was associated with a high immunogenic response and absence of MTCT.

Observational Study Evaluating the Seroprotection of HepB-alum Vaccine and HepB-CpG Vaccine in People With HIV.

Hepatitis B virus (HBV) vaccine seroprotection rates with conventional aluminum adjuvanted recombinant HBV vaccines, Engerix-B (HepB-alum) vaccine, among people with HIV (PWH) are varied. Heplisav-B (HepB-CpG) vaccine, a novel adjuvanted recombinant HBV vaccine, has shown higher seroprotection rates in immunocompetent patients but is not well studied in PWH. There are no published studies comparing seroprotection rates between HepB-alum and HepB-CpG in PWH. This study aims to evaluate and compare the seroprotection incidence of HepB-alum vs HepB-CpG in PWH at least 18 years of age. This retrospective, observational cohort study included adults diagnosed with HIV who received a complete series of HepB-alum or HepB-CpG at a community health center in Phoenix, Arizona. Patients had a hepatitis B surface antibody <10 IU/L at the time of the first vaccine dose. The primary outcome was a comparison of seroconversion incidence between HepB-CpG and HepB-alum. Secondary outcomes included identifying factors associated with likelihood of response to HBV vaccination. A total of 120 patients were included in this study, 59 in the HepB-alum cohort and 61 in the HepB-CpG cohort. In the HepB-alum cohort, 57.6% achieved seroconversion, compared with 93.4% in the HepB-CpG cohort (P < .001). Those without diabetes were more likely to have response to a vaccine. Among PWH at a single community health center, HepB-CpG provided a statistically higher incidence of seroprotection against HBV compared with HepB-alum.

Seroconversion following Heplisav-B, hepatitis B vaccine (recombinant), adjuvanted, in patients with end-stage renal disease at an urban safety net hospital.

Heplisav-B is a novel recombinant adjuvanted vaccine for hepatitis B virus (HBV) that has been approved as a 2-dose regimen and shown to have similar seroconversion rates in healthy adults as single-antigen HBV vaccines. More data are needed to determine whether similarly high rates of seroconversion and immunity are observed in immunocompromised patient populations such as in patients with end-stage renal disease (ESRD) on hemodialysis. Patients with ESRD who presented for emergency-only hemodialysis and either were HBV vaccine naive or had a hepatitis B surface antibody (anti-HBs) titer of less than 10 IU/mL received 3 standard 20-μg doses of Heplisav-B at week 0, week 4 (±2 weeks), and week 24 (±2 weeks), with anti-HBs titer measured at week 28 (±2 weeks). Thirty-two patients received at least one dose in the study timeframe, with 24 patients completing the vaccine series and measurement of anti-HBs titer. The mean age of the patients was 46 years, and 58% of patients were male. Of the 24 patients who completed the vaccine series, 20 (83%) seroconverted after the third dose. Three of the 4 patients who did not seroconvert after 3 doses were revaccinated with an additional 20-μg dose, and 2 of the 3 patients had an anti-HBs titer of greater than 10 IU/mL 4 weeks after this dose. Patients with ESRD who received three 20-μg doses of recombinant HBV vaccine had a seroconversion rate of 83%, representing a similar seroconversion rate and fewer doses of vaccine as compared to the standard HBV vaccine regimen for patients with ESRD.

Cholesterol accumulation on dendritic cells reverses chronic hepatitis B virus infection-induced dysfunction.

Chronic hepatitis B (CHB) infection remains a serious public health problem worldwide; however, the relationship between cholesterol levels and CHB remains unclear. We isolated peripheral blood mononuclear cells from healthy blood donors and CHB patients to analyze free cholesterol levels, lipid raft formation, and cholesterol metabolism-related pathways. Hepatitis B virus (HBV)-carrier mice were generated and used to confirm changes in cholesterol metabolism and cell-surface lipid raft formation in dendritic cells (DCs) in the context of CHB. Additionally, HBV-carrier mice were immunized with a recombinant HBV vaccine (rHBVvac) combined with lipophilic statins and evaluated for vaccine efficacy against HBV. Serum samples were analyzed for HBsAg, anti-HBs, and alanine aminotransferase levels, and liver samples were evaluated for HBV DNA and RNA and HBcAg. CHB reduced free cholesterol levels and suppressed lipid raft formation on DCs in patients with CHB and HBV-carrier mice, whereas administration of lipophilic statins promoted free cholesterol accumulation and restored lipid rafts on DCs accompanied by an enhanced antigen-presentation ability in vitro and in vivo. Cholesterol accumulation on DCs improved the rHBVvac-mediated elimination of serum HBV DNA and intrahepatic HBV DNA, HBV RNA, and HBcAg and promoted the rHBVvac-mediated generation and polyfunctionality of HBV-specific CD11ahi CD8αlo cells, induction of the development of memory responses against HBV reinfection, and seroconversion from HBsAg to anti-HBs. The results demonstrated the important role of cholesterol levels in DC dysfunction during CHB, suggesting that strategies to increase cholesterol accumulation on DCs might enhance therapeutic vaccine efficacy against HBV and support development toward clinical CHB treatment.

HUMORAL IMMUNITY RESPONSES AFTER VACCINATION FOR HEPATITIS B VIRUS IN AUTOGRAFTED PATIENTS: A SINGLE CENTER EXPERIENCE

The effectiveness of vaccinations post hematopoietic stem cell transplantation (HSCT), is a reliable marker for immune system's functionality assessment. In autologous HSCT (AHSCT) setting, the general aspect is that the immune system recovers quite soon and patients (pts) are considered to be immunocompetent in a period of approximately 3-6 months post AHSCT. We evaluated the hepatitis B virus (HBV) vaccination responses in autografted pts who were in remission and off chemotherapy post AHSCT. 27 autografted pts aged 51,6 (22-67) ys, who had antiHbs titers <10 IU/ml before AHSCT and at the time of vaccination, were studied. After a successful engraftment the median absolute lymphocytes count at +3 months was 1740(450-4090)/mm 3 . In 4,3(0,6–8,5) ys post AHSCT, 3 doses of recombinant HBV vaccine were given monthly. The response rates for pts who completed 3 vaccine doses, compared with an internal group of healthy individuals, vaccinated in the same period with the same product. After the 1 st , 2 nd and 3 rd dose the response rates in the study group were 11%, 81% and 88% respectively. No factor statistically significantly influenced the achievement of protective antiHbs titers. The responses were lower as compared to product's efficacy profile (19%, 86% and 100% after the 1 st , 2 nd and 3 rd dose respectively), while in the comparative analysis with the internal control group, a trend for inferior responses in autografted pts was also noticed (88% vs 100%, p=0,07). This study, in a relatively homogenous group of pts, to our knowledge, is the only one that directly compares the HBV vaccine responses in autografted pts with healthy individuals. Although vaccination was offered late post AHSCT, the responses were lower compared to healthy individuals, indicating a possible long lasting immune impairment post AHSCT highlighting the necessity of prolonged surveillance and intensified vaccination programs for autografted pts.

Hepatitis B Virus Vaccination after Allogeneic Hematopoietic Cell Transplantation Prevents Post-Transplantation Hepatitis B Virus Reactivation

Hepatitis B virus (HBV) reactivation in allogeneic hematopoietic cell transplantation (HCT) recipients with evidence of pretransplantation resolved HBV infection is an important cause of morbidity, usually occurring 1 year or later after HCT. We retrospectively studied a cohort of allogeneic HCT recipients with resolved HBV infection, some of whom were vaccinated for HBV following transplantation, to understand whether post-HCT HBV vaccination influenced the risk of HBV reactivation. The study included all patients with resolved HBV who underwent allogeneic HCT at our institution between January 1, 2000, and December 31, 2015, where HBV vaccination starting at 1 year after HCT became standard in 2012 and antiviral prophylaxis is not used. Resolved HBV infection was defined as positive HBV-core IgG (HBcAb), negative HBV-surface antigen (HBsAg), and undetectable HBV DNA before HCT. HBV reactivation was defined as the development of detectable HBsAg and HBV DNA after HCT. Follow-up for outcomes concluded on January 1, 2018. Among 136 patients with resolved HBV infection before HCT, 19 developed reactivation during follow-up (cumulative incidence, 14%). The median time to HBV reactivation was 21 months (range, 2 to 47 months). When accounting for competing risks, the cumulative incidence of HBV reactivation among HCT recipients who survived for 1 year or longer after transplantation without early HBV reactivation and were HBV vaccinated versus those who were unvaccinated was 2.9% versus 10.0% at 2 years post-HCT and 6.6% versus 26.5% at 4 years post-HCT (P=0.03, Gray's test). In a time-dependent Cox model, the adjusted hazard ratio (aHR) of HBV reactivation in patients with a pretransplantation HBsAb level >10 IU/L was 0.34 (95% confidence interval [CI], 0.13 -0.90). The aHR of HBV reactivation in patients who were vaccinated with 2 or more doses of recombinant HBV vaccine after HCT was 0.18 (95% CI, 0.04-0.80) compared with those who received 1 or no post-HCT vaccine doses. HBV reactivation is a late complication of allogeneic HCT in at-risk recipients, particularly in those with low pre-HCT HBsAb. HBV vaccination starting at 1 year after HCT may be protective.

Recombinant hepatitis B vaccine uptake and multiple sclerosis risk: A marginal structural modeling approach

BackgroundThere has been an ongoing debate regarding the association between uptake of recombinant vaccine against hepatitis B virus (HBV) and multiple sclerosis (MS) risk. This case-control study tested the hypothesis whether recombinant HBV vaccination status is causally associated with MS risk using targeted maximum likelihood estimation (TMLE) technique. MethodsConfirmed 110 MS cases and age (± 5 years), sex and nativity matched (1:1) 110 controls were enrolled. Data were collected on sociodemographics, environmental factors, history of vaccinations and past morbidities through face-to-face interview both from cases and controls. To estimate the causal parameters including marginal odds ratio (OR), causal relative risk (RR), causal risk difference (RD) and their 95% confidence intervals (CIs), we implemented case-control-weighted TMLE for a matched design that uses data-adaptive flexible stacked ensemble-based machine learning system namely Super Learner. Additionally, population preventable fraction (PPF) of MS risk was computed. ResultsThis study demonstrated a significant nonspecific protective effect of HBV vaccination against MS risk (marginal OR 0.44; 95% CI: 0.19–0.68; p = 0.006; causal RR 0.64, 95% CI: 0.46–0.89; p = 0.004). The significant causal RD showed that among the vaccinated 19% fewer MS cases occurred owing to their HBV vaccination (causal RD -0.19; 95% CI: -0.32 – -0.06; p = 0.014). In the source population, vaccination against HBV led to 17.4% reduced MS risk (PPF = 17.4%; 95% CI: 3.8%, 36.3%). ConclusionThe results suggest a significant nonspecific protective effect of recombinant HBV vaccine against MS risk. Future studies may contemplate to confirm these results.

Efficacy and Safety of Hepatitis B Virus Vaccination Following Hepatitis B Immunoglobulin Withdrawal After Liver Transplantation

Hepatitis B immunoglobulin (HBIG) and oral nucleoside/nucleotide analogs have been the mainstay of hepatitis B virus (HBV) prophylaxis after liver transplantation. However, long-term HBIG administration could have disadvantages, such as an increase in medical costs and the development of mutant HBV strains. This study aimed to investigate the safety and efficacy of HBV vaccination after the withdrawal of HBIG after liver transplantation. This prospective open-label single-arm observational clinical trial enrolled 41 patients who underwent liver transplantation between 2010 and 2016 because of a condition related to chronic HBV infection. At the time of enrollment, all patients had taken entecavir and discontinued HBIG administration. When hepatitis B surface antibody titer was undetectable after the withdrawal of HBIG, a recombinant HBV vaccine was injected intramuscularly at month 0, 1, and 6. After excluding 5 patients who dropped out and 2 patients who had a persistent hepatitis B surface antibody titer, 9 (26.5%) of 34 patients had a positive vaccination response. The median hepatitis B surface antibody titer at seroconversion was 86 (12-1000) IU/L, and those at the end of follow-up were 216 (30-1000) IU/L. No patients experienced HBV recurrence during the study period. Sex (female, odds ratio 32.91 [1.83-592.54], P=.018) and the dosing interval of HBIG before withdrawal (≥90 days, 16.21 [1.21-217.31], P=.035) were independent contributing factors for positive response to the vaccination. HBV vaccination still deserves consideration as active immunoprophylaxis after liver transplantation because it could provide added immunity to nucleoside/nucleotide analogs monotherapy with excellent cost-effectiveness.

Serological response with Heplisav-B® in prior Hepatitis B vaccine non-responders living with HIV

BackgroundAs people living with HIV (PLWH) are at risk for contracting Hepatitis B Virus (HBV), they should be screened for HBV and vaccinated if not immune. Seroconversion rates in PLWH receiving traditional recombinant HBV vaccines (Engerix-B® and Recombivax-HB®) have historically been low with at most 70% achieving immunity. In 2017, a recombinant, adjuvanted HBV vaccine (Heplisav-B®) was approved for use in HIV-negative patients.Heplisav-B® has shown superior seroprotection in this population compared to Engerix-B® and Recombivax-HB®, as well as interim analysis showing higher seropositivity rates in patients undergoing dialysis. However, its efficacy in PLWH is currently unknown. This study evaluates the rate of seroconversion following Heplisav-B® administration in PLWH with previous HBV vaccination failure. MethodsRetrospective, cross-sectional study at The Brooklyn Hospital Center’s HIV primary care clinic in Brooklyn, NY. HIV-positive adults who received at least two doses of Heplisav-B® and had previously failed to seroconvert after vaccination with Engerix-B® or Recombivax-HB® were included. The primary outcome is the percentage of PLWH who became seropositive following Heplisav-B®. ResultsA total of 67 patients met the inclusion criteria. Twenty-five (37.3%) PLWH had failed at least 2 courses of recombinant vaccines. Fifty-eight (86.6%) PLWH became seropositive (Anti-HBs > 10 mIU/mL) at least two months after completing Heplisav-B®. For the 9 (13.4%) patients that did not develop immunity, 3 (33%) had a detectable HIV RNA and 3 (33%) had a CD4 count < 200 cells/uL3. ConclusionsHeplisav-B® was highly effective in achieving immunity to HBV in PLWH who failed non-adjuvanted recombinant vaccines.

1321Marginal structural model of the causal role of hepatitis B vaccination in multiple sclerosis risk

Abstract Background There are conflicting reports regarding the association between uptake of recombinant vaccine against hepatitis B virus (HBV) and risk of multiple sclerosis (MS). Most cohort or case-control studies found no significant short- or long-term increase in MS risk after immunization. Whereas others reported a significant increase in MS risk within three years of HBV vaccination. The present matched case-control study was conducted to test the hypothesis whether recombinant HBV vaccination status is causally associated with MS risk using targeted maximum likelihood estimation (TMLE) that uses data-adaptive flexible machine learning algorithms to estimate the causal parameters. Methods Confirmed 110 MS incident cases and age (± 5 years), gender and nationality matched (1:1) 110 community controls were enrolled. A pre-tested structured questionnaire was used to collect the data on demographics, environmental factors, comorbidities, history of vaccinations through face-to-face interviews both from cases and controls. We implemented case-control-weighted TMLE – a double robust, multistep procedure to estimate causal relative risk (RR), marginal odds ratio (OR) and population attributable fraction. Results This study demonstrated a non-specific protective effect of HBV vaccine against MS risk as estimated by TMLE (causal RR 0.63, 95% CI: 0.45-0.90; p = 0.004; marginal OR 0.43; 95% CI: 0.18-0.67; p = 0.006). The population attributable fraction was 20% (95% CI: 6%, 34%; p = 0.014)) Conclusions Subject to inherent limitations of the case-control design, this study suggests a non-specific protective effect of recombinant HBV vaccination against MS risk. Future studies may contemplate to confirm these results. Key message Causal analysis showed a non-specific protective causal association between uptake of recombinant HBV vaccine and MS risk in the study population.

Effect of Revaccination with Recombinant Hepatitis B Virus Vaccine Containing Higher Antigen Concentration in Non-responder Children

BACKGROUND: Hepatitis B is a global health problem carrying significant morbidity and mortality. Vaccination against hepatitis B virus (HBV) has been implemented with good effectiveness, but a small proportion of children do not respond well after complete routine vaccination. They are called non-responders and are at higher risk for HBV infection.&#x0D; AIM: The objective of the study was to determine the effect of revaccination with recombinant HBV vaccine containing higher antigen concentration in non-responder children.&#x0D; METHODS: A prospective study was conducted from January 2018 until December 2019. Inclusion criteria were children aged 9–15 months and had three doses of recombinant HBV at 0, 1, and 6 months old. Exclusion criteria were the presence of acute or chronic hepatitis B and conditions which alter immune function and immunosuppressant medications consumption. Demographic and clinical characteristics were gathered from each subject along with serum HBsAb titer examination. Subjects with serum anti-hepatitis B surface antigen (HBsAb) titer of &lt;10 IU/L were classified into non-responders and underwent revaccination with 3 doses of vaccine containing 20 μg HBsAg. The revaccination series was repeated until all subjects showed seroconversion. After each series, repeated serum HBsAb titer measurements were conducted.&#x0D; RESULTS: A total of 400 children were enrolled in this study with a mean age of 12.1 (SD 2.64) months. Subjects were dominated with females (54.0) and normal nutritional status (79.0). The rate of non-responsiveness was 9.0%. Of all non-responders, 88.9% experienced seroconversion after the first revaccination series. After the third revaccination series, all subjects had serum HBsAb titer at the protective level.&#x0D; CONCLUSION: Revaccination with recombinant HBV vaccine containing higher antigen concentration in non-responder children is effective.

Factors affecting inadequate response to HBV vaccine in hemodialysis patients: northeast anatolia survey with six hemodialysis centers

In hemodialysis patients Hepatitis B virus (HBV) infection is one of the problems. Because of HBV vaccine response is lower than in the general population, in this study it is aimed to determine the factors that may cause inadequate HBV vaccine response in hemodialysis patients. In study, HBsAg, anti-HBs, anti-HBc IgG data belonging to 278 patients were obtained from file and computer records. It was seen that seronegative cases had been given recombinant HBV vaccine. Anti-HBs titers were monitored 1month after vaccination was completed. According to this, the patients are divided into two groups. Those with anti-HBs < 10IU/mL were identified as non-responders and with anti-HBs ≥ 10IU/mL as responders. Factors such as age, serum albumin and urea reduction rate which may affect inadequate response to HBV vaccine were evaluated. As statistical examination, Chi-square test was used for the analysis of the data determined by counting, and logistic regression was used for statistically significant independent variables in chi-square test. p value of < 0.05 was considered statistically significant (Confidence interval: 95%). Out of 278 patients, according to exclusion criteria 81 patients were excluded. 13.2%(26/197) of HBV vaccinated patients had insufficient response. The inadequate response rate to HBV vaccination was found to be higher in patients with age ≥ 65 (p = 0.039), serum albumin < 3.5g/dL (p = 0.024) and urea reduction rate ≤ 65 (p = 0.028). No statistically significant relationship was found between inadequate response to HBV vaccine and anti-HCV positivity, presence of diabetes mellitus, anemia status, vitamin D therapy and vascular access pathway variability. We conclude that relatively high patient age, low albumin level and insufficient urea reduction rate may cause inadequate HBV vaccine response. Taking these factors into consideration may provide a useful insight for an adequate response to vaccination.

Monitoring the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children: Protective anti-HBs levels and cellular immune responses

Vaccination against hepatitis B virus (HBV) is recommended worldwide. The aim of this study was to assess the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children in the context of protective anti-HBs levels and cellular immune responses. Using a random questionnaire survey, 1695 pre-school children were recruited as research subjects during January 2015 to June 2017. Blood samples were obtained to measure HBV serological markers as well as peripheral immunocytes. The children were divided into non-, low- and hyper- responsive groups (NR, LR, and HR) based on the vaccination efficacy. Additionally, the effect of revaccination on the NR group was evaluated at 1 month after completion of the vaccination course. Among a total of 1695 children, 1591 (93.86%) were infants who were followed while undergoing their primary course of hepatitis B vaccination at the 0-1-6 month schedule, and 1249 (79.30%) of them developed antibodies against HBsAg (anti-HBs) titers greater than 10 IU/L. The results of immunocyte studies indicated that the CD8+ T cells, CD4+CD45RO+ T cells, CD8+CD45RA+ T cells, and T follicular helper (Tfh) cells increased significantly in NR compared with HR. However, lymphocytes, CD4+ T cells, and CD4+CD45RA+ T cells in NR were lower than that in HR. 96 of the non-response cases showed seroprotection after revaccination among 103 cases. Therefore, most of the preschool children who received hepatitis B vaccine in infancy achieved significant seroprotection. Seroconversion rates of individuals revaccinated after initial vaccination failure were significantly higher than those after primary vaccination. Different vaccination efficacy groups showed significant changes in circulating immunocytes, which might be a factor affecting the recombinant HBV vaccine’s immune effectiveness.

Mushroom lectin overcomes hepatitis B virus tolerance via TLR6 signaling

Currently, chronic hepatitis B virus (HBV) infection remains a serious public health problem in the world. Recombinant HBV vaccine, as a preventive strategy against HBV infection, generates high antibody level, but it is not effective to activate innate and cellular immunity for chronic HBV infection therapy. Lectins from mushroom are natural and active proteins which have been shown important biological functions. However, little is known about the immunological mechanism engaged by mushroom lectins. Here we report that, lectin from Pleurotus ostreatus (POL) stimulated innate response by activating Toll-like receptor 6 signal pathway of dendritic cells. Subsequently POL enhanced HBV specific antibody level and follicular helper T cells response which overcame HBV tolerance in transgenic mice. This study suggests a novel mechanism for POL acting on immune response and a therapeutic approach to break HBV tolerance.

Efficacy of Hepatitis B Virus Vaccination and Antibody Response to Reactivation Dose Among Adult Non-Responders to Primary Hepatitis B Vaccination in Chronic Hepatitis C Egyptian Patients

BACKGROUND AND AIMS: Acute HBV infection in patients with chronic HCV-related liver disease is associated with a severe and often fulminant course of the disease. Additionally, HCV patients may be at a higher than an average risk of acquiring hepatitis B because of the similar routes of transmission of both viruses. HBV infection can be prevented by the administration of a safe and immunogenic vaccine. Insufficient immune response to hepatitis B virus (HBV) vaccine in patients with chronic hepatitis C virus is frequently encountered and anti-HBs levels may persist for a shorter time than among immune competent persons. The purpose of present study was to determine long-term persistence of anti-HBs among Egyptian patients with chronic hepatitis C infection. It also assesses the need and response to a subsequent challenge with vaccine booster doses. METHODS: 200 individuals were enrolled; (GI) 100 patients suffered from chronic HCV infection and 100 healthy individuals as a control (GII). Both groups were matched in regard to age and sex. Each individual received a standard 3-dose series of HBV vaccine; 20µg recombinant DNA vaccine of HBV(Euvax-B LG Life science, Korea) administered by IM injection into deltoid muscle at 0, 1, 6 months interval. HBs antibody titer was measured after 4 weeks. Suboptimal or Non-responders (anti-HBs titer < 10 IU/L) received a booster dose and reevaluated after 4 weeks; Suboptimal response of group I (42 patients) divided into 2 subgroups: GIa (21 patients), which received 40 µg(double dose) recombinant HBV vaccine and GIb (21 patients), received standard adult dose 20 µg HBV vaccine. 11 individuals with suboptimal response of G II received standard adult dose 20 µg HBV vaccine too. CONCLUSION: Chronic HCV patients showed lower response rate for standard doses of HBV vaccine especially with advancing age, diabetes and hypoalbuminemia. A double booster dose (40 μg) vaccine would be recommended for them which are better than revaccination with the standard 3 doses recombinant HBV vaccine.

Development of an in-House TaqMan Real-Time PCR-Based Method to Detect Residual Host Cell DNA in HBV Vaccine.

Biological therapeutic products such as recombinant hepatitis B virus (HBV) vaccine, produced by microbial fermentation in complex media, should be evaluated for host cell DNA contamination in purification steps. Eliminating these contaminations increases the efficacy of the vaccine and decreases its side effects. The objective of the present study is to trace the residual host cell DNA (HCD) in recombinant HBV vaccine by developing a TaqMan Real-Time PCR method which is more sensitive, specific, and reproducible than traditional methods such as Picogreen analysis and Threshold DNA assay. Primers and a probe were designed for the most highly conserved regions of Pichia pastoris genome. To determine the specificity of the assay, in addition to performing a BLAST for the primers and the probe in NCBI nucleotide database, 20 different human genomes and 8 bacterial and viral genomes were used. Moreover, serial dilutions of plasmids, from 10(2) to 10(7) copies/μL (from 0.00064 to 6.4pg/μL), were prepared to find the sensitivity and the limit of detection (LOD) of the assay. Using 28 different genome samples, the specificity of the assay was determined to be 100%. In addition, the sensitivity and LOD of the method was 0.39 × 10(-5)pg/μL. Moreover, the reproducibility of the assay based on intra- and inter-assay was 1.03 and 1.06%, respectively. Considering the suitable specificity and sensitivity, ease of use, relatively low cost, and rapidity of the assay, it can be a reproducible and sensitive method to examine recombinant vaccines for P. pastoris residual DNA.

Novel perspectives on the hepatitis B virus vaccine in the chronic kidney disease population.

The prevalence and incidence rates of hepatitis B virus (HBV) among patients undergoing maintenance dialysis in developed countries have declined over the last 2 decades thanks to the implementation of numerous infection control procedures in dialysis units, including the hepatitis B vaccine. It is well known that the immune response against HBV vaccine is unsatisfactory in the chronic kidney disease (CKD) population. The seroprotection rate after the HB vaccine schedule is low and the anti-HB titers are reduced, falling logarithmically over time. We did an extensive review of the medical literature on the mechanisms underlying the reduced response rate towards the HBV vaccine in patients with CKD. The efficacy and safety of HBV vaccines for use in the CKD population was also evaluated. Currently available vaccines against HBV are mostly plasma-derived or manufactured by recombinant DNA technology (yielding the S protein of the HBV envelope). The most promising strategy to enhance the immune response toward the HBV vaccine in the dialysis population is given by adjuvanted vaccines. Second-generation recombinant HB vaccines provided with a novel adjuvant (AS04, made of 3-O-4'-desacyl-monophosphoryl lipid A adsorbed on aluminum phosphate) demonstrated improved immunogenicity but a number of patients with an unsatisfactory response still occurs. Additional second-generation vaccines containing nonaluminum-based adjuvant systems such as AS02 (3-O-desacyl-4'-monophoshoryl lipid A and QS21) or 1018 (a Toll-like receptor 9 agonist) have shown higher immunogenicity and acceptable safety in the CKD population. The evidence in patients with end-stage renal disease is extremely limited on the use of third-generation vaccines, recombinant HBV vaccines expressed in mammalian cells containing S/Pre-S antigens. The immunogenicity of HBV vaccines in patients with CKD is suboptimal but novel technologies promise to give better results in the near future.

Predictors of Booster Response to Hepatitis B Vaccine at 15 years of age: A Cross-Sectional School-Based Study

The current consensus does not support the use of booster dose because of its anamnestic response in almost all children 15 years after universal infant hepatitis B virus (HBV) vaccination. However, in our clinical setting, numerous concerned parents request a booster administration for their children. We aimed to provide the possible predictors of booster response in adolescents before this booster administration. This study comprised a series of cross-sectional serological surveys of HBV markers in 15-year-old individuals between 2008 and 2012. Data on serum hepatitis B surface antigen, hepatitis B surface antibody (anti-HBs), and liver-function biomarkers in a total of 887 senior high-school students were collected. There were two parts to this study: HBV seroepidemiology and booster-response analysis to identify the possible response predictors and decay factors after the HBV booster administration. The overall anti-HBs and hepatitis B surface antigen seropositivity rates were 34.7% and 0.7%, respectively, and the median anti-HBs titer was 3.3mIU/mL. Six weeks after one dose of recombinant HBV vaccine, the overall booster-response rate in the double-seronegative recipients was 94% (471/501). Among the participants whose initial anti-HBs titers were undetectable or low, 72.4% (247/341) and 95.6% (153/160), respectively, reactivated their anti-HBs titers≥100mIU/mL about 6 weeks after the booster administration. The likelihood of postbooster anti-HBs titer reaching an adequate protective level increased with the prebooster titer. The female participants had stronger anamnestic responses compared to the male participants. We found that the female participants and prebooster anti-HBs titers above the detection limit of the immunoassay were good predictors of HBV booster response.

Extending the Debate on Poor Response to Hepatitis B Virus Vaccination in Children With Celiac Disease: Which Question Remains?

Dear Editor, A poorer response to hepatitis B vaccination, in coeliac subjects, compared to healthy subjects, has been largely debated. Almost all authors postulated that human leukocyte antigen (HLA) genotype DQ2, found in 90 - 95% of coeliac patients, could represent the main cause in determining the impaired antibody response to recombinant HBV vaccine (1), as well as observed also in healthy not responder subjects. However it has been supposed that gluten intake could represent the main factor in influencing a poorer response to vaccine, since in several studies, it has been observed that the percentage of responders in patients compliant with a gluten free diet (GFD) was similar to healthy subjects (2, 3). Since type I diabetes (T1DM) and coeliac disease (CD) have the same genetic background, given by the HLA molecules that have also been identified as haplotypes associated with unresponsiveness to hepatitis B virus (HBV) vaccination (DR3 and DR4 for T1DM, DQ2 and DQ8 for CD), we firstly compared three different groups of patients, corresponding to T1DM, CD and DMT1-CD, that had in common the same HLA haplotypes, to establish the weight of specific haplotypes of HLA and/or gluten that could favor a poorer response to HBV vaccine. In 30 children suffering from both CD and DMT1, vaccinated by the administration of three doses of vaccine (Engerix-B, Glaxo Smith Kline, London, United Kingdome) at the age of 3, 5 and 11 months of life, according to the national vaccination schedule, we discovered 16 (53.3%) non-responders. This percentage was similar to a previous study on 60 coeliac patients (4), although not significantly higher, compared to a previous study on 100 diabetics (5) (Table 1). Table 1. Characteristics of Patients With Type 1 Diabetes Mellitus, Celiac Disease and Associated Type 1 Diabetes Mellitus/Coeliac Disease a As the mean age and the anti-HBs antibodies titers was similar between coeliacs and coeliacs/diabetics, we consider that the presence of T1DM and its HLA haplotype seems to not decrease anti-HBs antibodies production and percentage of responders. The open question is: what is the role of gluten in this matter? Comparing the T1DM/CD and T1DM, in which both groups had a similar HLA haplotype, we found a higher non-significant percentage of non-responders in T1DM/CD than in T1DM (53.3% vs. 38.2%), although the first group even had a significantly lower mean age (P < 0.0001), which usually is associated to a higher titer of anti HBs antibodies (P < 0.02) and a higher percentage of responders, as we also found in our study (Table 1). The question still remains open: what is the role of gluten in this matter? First of all, we observed that the percentage of non-responders is higher in T1DM/CD patients, compared with diabetics (53.3% vs. 38.2%). However, if we compare the first group with coeliacs, the percentage of non-responders is similar (53.3% vs. 50%). As the genetic substrate of HLA haplotypes, in the two diseases, is the same, this comparison indirectly confirms that gluten certainly represents a second variable, which favors a further decrease of efficacy to HBV vaccine, beyond the HLA system. As written in 1890 by in the chapter “The Science of Deduction” of the book “The Sign of Four, eliminate all other factors and the one which remains must be the truth (6).”

Overcoming HBV immune tolerance to eliminate HBsAg-positive hepatocytes via pre-administration of GM-CSF as a novel adjuvant for a hepatitis B vaccine in HBV transgenic mice.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to be a potential vaccine adjuvant despite contradictory results from animal and human studies. The discrepancies may be due to the different doses and regimens of GM-CSF that were used, given that either mature or immature dendritic cells (DCs) could be induced under different conditions. To test the hypothesis that GM-CSF can be used as a novel adjuvant for a hepatitis B virus (HBV) therapeutic vaccine, we administered GM-CSF once per day for three days prior to vaccination with recombinant HBV vaccine (rHBVvac) in mice. We observed greater DC maturation in these pre-treated animals at day 3 as compared to day 1 or day 2 of daily GM-CSF administration. This strategy was further investigated for its ability to break the immune tolerance established in hepatitis B surface antigen-transgenic (HBsAg-Tg) animals. We found that the levels of induced anti-HBsAg antibodies were significantly higher in animals following three days of GM-CSF pre-treatment before rHBV vaccination after the third immunization. In addition to the increase in anti-HBsAg antibody levels, cell-mediated anti-HBsAg responses, including delayed-type hypersensitivity, T-cell proliferation, interferon-γ production, and cytotoxic T lymphocytes, were dramatically enhanced in the three-day GM-CSF pre-treated group. After adoptive transfers of CD8+ T cells from immunized animals, antigen-specific CD8+ T cells were observed in the livers of recipient HBsAg-Tg animals. Moreover, the three-day pre-treatments with GM-CSF prior to rHBVvac vaccination could significantly eliminate HBsAg-positive hepatocytes, suggesting beneficial therapeutic effects. Therefore, this protocol utilizing GM-CSF as an adjuvant in combination with the rHBVvac vaccine has the potential to become a novel immunotherapy for chronic hepatitis B patients.