anti-HBs Antibody Response Research Articles

Hepatitis B vaccine delivered by microneedle patch: Immunogenicity in mice and rhesus macaques.

Vaccination against hepatitis B using a dissolving microneedle patch (dMNP) could increase access to the birth dose by reducing expertise needed for vaccine administration, refrigerated storage, and safe disposal of biohazardous sharps waste. In this study, we developed a dMNP to administer hepatitis B surface antigen (HBsAg) adjuvant-free monovalent vaccine (AFV) at doses of 5µg, 10µg, and 20µg, and compared its immunogenicity to vaccination with 10µg of standard monovalent HBsAg delivered by intramuscular (IM) injection either in an AFV format or as aluminum-adjuvanted vaccine (AAV). Vaccination was performed on a three dose schedule of 0, 3, and 9weeks in mice and 0, 4, and 24weeks in rhesus macaques. Vaccination by dMNP induced protective levels of anti-HBs antibody responses (≥10 mIU/ml) in mice and rhesus macaques at all three HBsAg doses studied. HBsAg delivered by dMNP induced higher anti-HBsAg antibody (anti-HBs) responses than the 10µg IM AFV, but lower responses than 10µg IM AAV, in mice and rhesus macaques. HBsAg-specific CD4+ and CD8+ T cell responses were detected in all vaccine groups. Furthermore, we analyzed differential gene expression profiles related to each vaccine delivery group and found that tissue stress, T cell receptor signaling, and NFκB signaling pathways were activated in all groups. These results suggest that HBsAg delivered by dMNP, IM AFV, and IM AAV have similar signaling pathways to induce innate and adaptive immune responses. We further demonstrated that dMNP was stable at room temperature (20°C-25°C) for 6months, maintaining 67±6 % HBsAg potency. This study provides evidence that delivery of 10µg (birth dose) AFV by dMNP induced protective levels of antibody responses in mice and rhesus macaques. The dMNPs developed in this study could be used to improve hepatitis B birth dose vaccination coverage levels in resource limited regions to achieve and maintain hepatitis B elimination.

Immune Response to anti-HBs Antibodies in Health Workers Following Hepatitis B Vaccination

According to Regulation No. 53 of 2015 of the Minister of Health of the Republic of Indonesia, a high risk of HBV infection in health workers is a problem that requires attention, and vaccination knowledge is critical to reducing these risk factors. Furthermore, because some people do not produce a sufficient antibody-forming (anti-HBs) response to HBsAg, testing for evidence of protective immunity against hepatitis B vaccination is required (Hepatitis B Surface Antigen). The purpose of the study was to determine the mapping of the characteristics of anti-HBs antibodies response after hepatitis B vaccination in health workers in terms of age, gender, ethnicity, smoking habits, obesity, vaccination frequency, last time of vaccination. Sixty vaccinated health workers were used to creating the research sample. Anti-HBs levels/titers in serum were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) method, and a questionnaire was used to compile the data for this study. Age, gender, smoking, obesity, and vaccination dose were all used to map the outcomes of the anti-HBs antibody immune response study. Anti-HBs antibody response in health workers was graded as poor in 36 people (60%) and strong in 24 (40%). Regarding ethnic origin, lifestyle, obesity, and vaccination dose (frequency), there was no significant link between post-vaccination anti-HBs antibody response in health workers. In terms of age and gender, there is a strong association between post-vaccination anti-HBs antibody responses in health workers. Low antibody titers should be revaccinated to enhance anti-HBs titers, and health workers who smoke should quit because it reduces the levels of anti-HBs titers produced clinically.

Assessment of the anti-HBs antibody response in Beninese infants following 4 doses of HBV vaccine, including administration at birth, compared to the standard 3 doses regime; a cross-sectional survey

Hepatitis B virus (HBV) infection remains one of the major neglected health issues worldwide. In sub-Saharan Africa (SSA), HBV endemicity is high, with more than 8% of the population being chronic HBV carriers. Recently, WHO recommended that all infants should receive their first dose of the HBV vaccine as soon as possible after birth. Unfortunately, the incorporation of a birth dose of HBV in the expanded programme immunization (EPI) has not occurred in the majority of countries in SSA. From April to September 2017, a cross-sectional survey was conducted in two vaccine units located in southern Benin. We assessed the sustained anti-HBs antibody response in infants induced by a standard scheme of 3 doses of HBV vaccination (6, 10, 14 weeks) in comparison to a scheme of 4 doses with a birth dose included (0, 6, 10, 14 weeks). Blood samples were systematically collected in the first 140 children aged 9 months and their mothers who had consented to participate for the detection of HBs antigen and the quantification of anti-HBs antibodies. The prevalence of HBV infection among infants and mothers was 2.2% and 7.1%, respectively. Infants who received 4 doses of HBV vaccine had a significantly higher level of anti-HBs antibody than those who received 3 doses of vaccine (557.9 UI/L vs. 386.9 UI/L, respectively, P = 0.03). We also showed that the scheme of 4 doses was associated with a significantly higher sustained protective response in comparison to the scheme of 3 doses (aOR 2.49, 95% CI 1.03–6.03, P = 0.04). This result provides further evidence of the importance of administering HBV vaccine at birth, but also highlights the importance for the prevention of vertical transmissions. Additional studies are needed to better establish the cost-effectiveness of such a 4 doses immunization strategy before implementing the HBV vaccination at birth in the EPI.

Toward a Functional Cure for Hepatitis B: The Rationale and Challenges for Therapeutic Targeting of the B Cell Immune Response.

The central role of the cellular immune response in the control and clearance of the hepatitis B virus (HBV) infection has been well-established. The contribution of humoral immunity, including B cell and antibody responses against HBV, has been investigated for a long time but has attracted increasing attention again in recent years. The anti-HBs antibody was first recognized as a marker of protective immunity after the acute resolution of the HBV infection (or vaccination) and is now defined as a biomarker for the functional cure of chronic hepatitis B (CHB). In this way, therapies targeting HBV-specific B cells and the induction of an anti-HBs antibody response are essential elements of a rational strategy to terminate chronic HBV infection. However, a high load of HBsAg in the blood, which has been proposed to induce antigen-specific immune tolerance, represents a major obstacle to curing CHB. Long-term antiviral treatment by nucleoside analogs, by targeting viral translation by siRNA, by inhibiting HBsAg release via nucleic acid polymers, or by neutralizing HBsAg via specific antibodies could potentially reduce the HBsAg load in CHB patients. A combined strategy including a reduction of the HBsAg load via the above treatments and the therapeutic targeting of B cells by vaccination may induce the appearance of anti-HBs antibodies and lead to a functional cure of CHB.

Antibody Responses Specific to Hepatitis B Virus Vaccine in Children Exposed InUtero to Antiretroviral Therapy

The use of antiretroviral (ARV) has been one of the most effective means of preventing vertical transmission of the human immunodeficiency virus (HIV) to exposed children born of HIV infected mothers. Nevertheless, responses to childhood vaccination against Hepatitis B virus (HBV) infections remain suboptimal in HIV exposed uninfected children irrespective of maternal ARV prophylaxis. In a cross-sectional study we have assessed the impact of in-utero exposure to ARV on paediatric HBV vaccination. Anti-HBV surface antigen specific antibodies (anti-HBs abs) were measured in plasma specimens from 44 healthy children unexposed to both HIV and ARV (HU), 25 HIV-exposed uninfected children naïve to intrauterine exposure to ARV (HEU.AR - ), 29 ARV and HIV-exposed uninfected children during pregnancy (HEU.ARV +), 50 children vertically infected with HIV but naïve to intrauterine exposure to ARV (HEI.ARV - ) and 22 children vertically infected with HIV with in utero exposure to ARV (HEI.ARV +). The protective seroconversion rate after childhood HBV vaccination (anti-HBs ≥10 mUI/ml) among HEU.ARV + children (58%) was significantly lower relative to both HEU.ARVc - (100%, P=0.0010) and the healthy unexposed children (92 %, P=0.0069). Similarly, HEI.ARV + children also had significantly lower anti-HBs IgM antibody responses when compared to both HU (p=0.0003) and HEI.ARV - (0.0001) children respectively. Thus in-utero exposure to ARV probably contributes in reducing HBV vaccine antibody response rate in both HIV exposed uninfected and vertically infected children after childhood vaccination. Nevertheless, the overall impact of ARV was to improve anti-HBs IgG responses in HIV infected children suggesting a possible role in immune reconstitution leading to improved IgG antibody responses.

A unique B cell epitope-based particulate vaccine shows effective suppression of hepatitis B surface antigen in mice

ObjectiveThis study aimed to develop a novel therapeutic vaccine based on a unique B cell epitope and investigate its therapeutic potential against chronic hepatitis B (CHB) in animal models.MethodsA series...

PASylated interferon α efficiently suppresses hepatitis B virus and induces anti-HBs seroconversion in HBV-transgenic mice

Interferon α (IFNα) so far is the only therapeutic option for chronic hepatitis B virus (HBV) infection that can lead to virus clearance. Unfortunately, its application is limited by side effects and response rates are low. The aim of this study was to generate a novel long-acting IFNα with the help of PASylation technology that adds a polypeptide comprising Proline, Alanine and Serine (PAS) to increase plasma half-life. Following evaluation of four selected recombinant murine IFNα (mIFNα) subtypes in cell culture, the most active subtype, mIFNα11, was fused with a 600 amino acid PAS chain. The activity of PAS-mIFNα was assessed by interferon bioassay and further evaluated for induction of interferon-stimulated genes (ISG) and antiviral efficacy in cell culture as well as in HBV-transgenic mice. PAS-mIFNα induced expression of ISG comparable to unmodified mIFNα and, likewise, evoked dose-dependent reduction of HBV replication in vitro. In vivo, PAS-mIFNα led to pronounced suppression of HBV replication without detectable liver damage whereas conventional mIFNα treatment only had a modest antiviral effect. Importantly, all PAS-mIFNα treated mice showed an anti-HBs antibody response, lost HBsAg and achieved seroconversion after three weeks. PASylated IFNα showed a profoundly increased antiviral effect in vivo compared to the non-modified version without toxicity, providing proof-of-concept that an improved IFNα can achieve higher rates of HBV antiviral and immune control.

Response of Preterm Infants of Mothers Who Are Chronic Carriers of Both HBsAg and HBeAg to Pre-52 Containing Hepatitis 8 Vaccine (TGP 943) - A Preliminary Report

This study aimed to examine the immunogenccity and protective efficacy of a pre-S2 containing hepatitis B vaccine (TGP 943, Takada, Japan) in 9 preterrn infants. A control group of preterm infants were given plasma derived hepatitis B vaccine (Korean Green Cross, Korea). All these preterm infants were born to both HBsAG and HBeAg posistive mothers and born in central General Hospital Sanglah Denpasar from January 3, 1992 to October 30, 1992. The gestational ages were 35-37 weeks and birth weights were 2000-2500 grams. The difference of the anti pre-S2 antibody between two groups of preterm infants was evident at month 6. Anti-HBs antibody response was almost same in the two groups of preterm infants. None in preterm infants in this study became positive for HBsAg during follow-up for at least 6 months. 2 of 8 preterm infants in control group become positive for HBsAg during follow up for a t least 6 months. Our study demonstrated a better anti pre-S2 antibody response and also comparable anti-Hbs antibody response in preterms infants vaccinated with a pre-S2 containing hepatitis B vaccine, compared with those with conventional plasma-derived vaccine.

The association of the vitamin D status with the persistence of anti-HBs antibody at 20 years after primary vaccination with recombinant hepatitis B vaccine in infancy

Vitamin D has potent immunoregulatory effects due to the expression of its receptor on the majority of immune cells. The aim was to evaluate the association of the vitamin D status with the persistence of anti-HBs antibody and immune response to booster immunization at 20years after primary vaccination with hepatitis B (HB) vaccine. Blood samples were collected from 300 adults 20years after completion of the primary HB vaccination in infancy. The serum levels of vitamin D and anti-HBs antibody were measured by ELISA. A single booster dose of a recombinant HB vaccine was administered to a total of 138 subjects, whose anti-HBs titer was<10IU/L. The sera of revaccinated subjects were re-tested for anti-HBs antibody, 4weeks after booster vaccination. At 20years after primary vaccination, the mean vitamin D concentrations were significantly higher in seroprotective subjects as compared to non-seroprotective individuals (P<0.01). The levels of anti-HBs were significantly increased with advanced concentrations of vitamin D (P<0.01). Overall, 125/138 (90.6%) of the revaccinated subjects showed an anamnestic response to booster vaccination. The concentrations of vitamin D were significantly higher in subjects with an anamnestic response to booster vaccination as compared with subjects without this response (P<0.01). Vitamin D status may influence the persistence of anti-HBs antibody and durability of protection after primary vaccination with a recombinant HB vaccine in infancy.

The persistence of anti-HBs antibody and anamnestic response 20 years after primary vaccination with recombinant hepatitis B vaccine at infancy

Hepatitis B (HB) vaccine induces protective levels of antibody response (anti-HBs ≥ 10 mIU/mL) in 90–99% of vaccinees. The levels of anti-HBs antibody decline after vaccination. The aim of this study was to evaluate the persistence of anti-HBs antibodies and immunologic memory in healthy adults at 20 years after primary vaccination with recombinant HB vaccine. Blood samples were collected from 300 adults at 20 years after primary HB vaccination and their sera were tested for anti-HBs antibody by ELISA technique. A single booster dose of HB vaccine was administered to a total of 138 subjects, whose anti-HBs antibody titer was <10 mIU/mL. The sera of subjects were re-tested for the anti-HBs antibody levels at 4 weeks after booster vaccination. At 20 years after primary vaccination 37.0% of participants had protective levels of antibody with geometric mean titer (GMT) of 55.44 ± 77.01 mIU/mL. After booster vaccination, 97.1% of vaccinees developed protective levels of antibody and the GMT rose from 2.35 ± 6.49 mIU/mL to 176.28 ± 161.78 mIU/mL. 125/138 (90.6%) of re-vaccinated subjects also showed an anamnestic response to booster vaccination. At 20 years after primary vaccination with HB vaccine, low proportion of the subjects had protective levels of antibody. However, the majority of the re-vaccinated subjects developed protective levels of anti-HBs and showed an anamnestic response after booster vaccination. Additional follow-up studies are necessary to determine the duration of immunological memory.

Safety and Immunogenicity of Hepatitis B Vaccine: a Study on Iranian Navy Personnel

Preventing communicable diseases in the armed forces (AF) of a country is considered as a national interest and has a great importance. There are limited data on the efficacy of vaccination of the navy personnel. This study was designed to evaluate both the safety and the immunogenicity of a recombinant hepatitis B (HB) vaccine made by Pasteur Institute of Iran (IPI-rHB), in this target group. Methods: In this study, all members of two navy units were enrolled. After measuring their amount of primary antibody, the subjects were selected for vaccination. Finally, 108 male volunteers were surveyed who were all between 25 to 45 years of age. Three doses of IPI-rHB vaccine (1 ml containing 20µg of the recombinant antigen) were administered to the subjects who were serologically negative for HB markers. The vaccination was given intramuscularly via the deltoid muscle according to the 0, 1 and 6 months schedule. The subjects were carefully monitored to record any adverse reaction of the vaccine. Blood specimens were collected from each subject, 1 month after the second and third vaccinations, in order to determine the anti-HBs antibody response to the vaccine. The obtained serum was tested by ELISA to quantify anti-HBs antibodies raised in each subject. Results: The results showed that local pain, fever, erythema, induration, nausea, vomiting and headache were the significant side effects noted. Protective antibodies (anti-HBs) were detected with seroconversion and seroprotection rates of 52.9% and 47.1%, respectively after the second dose and seroconversion and seroprotection rates of 100% and 93.51% after the third dose of the vaccine. After completing the vaccination; in 101 (93.51%) of the participants, antibody level was greater than 10 mIU/ml and in 7 (6.48%) subjects, the antibody level was between 1 and 10 mIU/ml. After the vaccination, the geometric mean titer of anti-HB antibody was 132.85. The seroprotection rate was 93.51% among the vaccinated population and 6.48% of the participants showed seroconversion. In this study, 22 (20.37%) subjects had anti-HBs titer of 10-100 mIU/ml and 79% (73.15%) subjects had anti-HBs titer of greater than100 mIU/ml. Although immunity to HB was achieved to a protective level among all the participants, the assessment of the long term immunity in AF members after complete vaccination is recommended. Conclusion: the results emphasized the importance of HB vaccination in adults, especially the AF members. Moreover, it reinforced the fact that three doses of HB vaccine is necessary to increase the seropositivity rate of anti-HBsAg in this group.

Efficacy of ABX196, a new NKT agonist, in prophylactic human vaccination

We have assessed the immune-regulatory and adjuvant activities of a synthetic glycolipid, ABX196, a novel analog of the parental compound α-GalCer. As expected, ABX196 demonstrated a measurable and significant adjuvant effect in mice and monkeys with no appreciable toxicity at the doses used to promote immune responses. We performed a phase I/II dose escalation study of ABX196 in healthy volunteers, with the objectives to evaluate its safety profile, as well as its ability to be utilized as an adjuvant in the context of a prophylactic vaccine against hepatitis B. ABX196 was administered at three doses: 0.2, 0.4, and 2.0μg, in 44 subjects. In all the individuals injected with ABX196, peripheral blood NKT cells displayed hallmarks of activation, and 45% of them had measurable circulating IFN-γ 24h after the first administration. More importantly, the addition of ABX196 to the very poorly immunogenic HBs antigen resulted in protective anti-HBs antibody responses in majority of patients, demonstrating the adjuvant properties of ABX196 in human. Further analysis of the cohort of subjects receiving ABX196 with HBs antigen also indicates that a single injection appears sufficient to provide protection. A limited set of adverse events linked to the systemic delivery of ABX196 and access to the liver, is discussed in the context of formulation and the need to limit transport of ABX196 to secondary lymphoid tissues for maximal efficacy (Eudra-CT 2012-001566-15).

Construction and immunological evaluation of truncated hepatitis B core particles carrying HBsAg amino acids 119–152 in the major immunodominant region (MIR)

Hepatitis B capsid protein expressed in Escherichia coli can reassemble into icosahedral particles, which could strongly enhance the immunogenicity of foreign epitopes, especially those inserted into its major immunodominant region. Herein, we inserted the entire ‘α’ antigenic determinant amino acids (aa) 119–152 of HBsAg into the truncated HBc (aa 1–144), between Asp78 and Pro79. Prokaryotic expression showed that the mosaic HBc was mainly in the form of inclusion bodies. After denaturation with urea, it was dialyzed progressively for protein renaturation. We observed that before and after renaturation, mosaic HBc was antigenic as determined by HBsAg ELISA and a lot of viruslike particles were observed after renaturation. Thus, we further purified the mosaic viruslike particles by (NH4)2SO4 precipitation, DEAE chromatography, and Sepharose 4FF chromatography. Negative staining electron microscopy demonstrated the morphology of the viruslike particles. Immunization of Balb/c mice with mosaic particles induced the production of anti-HBs antibody and Th1 cell immune response supported by ELISPOT and CD4/CD8 proportions assay. In conclusion, we constructed mosaic hepatitis core particles displaying the entire ‘α’ antigenic determinant on the surface and laid a foundation for researching therapeutic hepatits B vaccines.

Therapeutic recovery of hepatitis B virus (HBV)-induced hepatocyte-intrinsic immune defect reverses systemic adaptive immune tolerance

Hepatitis B virus (HBV) persistence aggravates hepatic immunotolerance, leading to the failure of cell-intrinsic type I interferon and antiviral response, but whether and how HBV-induced hepatocyte-intrinsic tolerance influences systemic adaptive immunity has never been reported, which is becoming the major obstacle for chronic HBV therapy. In this study, an HBV-persistent mouse, established by hydrodynamic injection of an HBV-genome-containing plasmid, exhibited not only hepatocyte-intrinsic but also systemic immunotolerance to HBV rechallenge. HBV-specific CD8(+) T-cell and anti-HBs antibody generation were systemically impaired by HBV persistence in hepatocytes. Interestingly, HBV-induced hepatocyte-intrinsic immune tolerance was reversed when a dually functional vector containing both an immunostimulating single-stranded RNA (ssRNA) and an HBx-silencing short hairpin RNA (shRNA) was administered, and the systemic anti-HBV adaptive immune responses, including CD8(+) T-cell and anti-HBs antibody responses, were efficiently recovered. During this process, CD8(+) T cells and interferon-gamma (IFN-γ) secreted play a critical role in clearance of HBV. However, when IFN-α/β receptor was blocked or the Toll-like receptor (TLR)7 signaling pathway was inhibited, the activation of CD8(+) T cells and clearance of HBV was significantly impaired. These results suggest that recovery of HBV-impaired hepatocyte-intrinsic innate immunity by the dually functional vector might overcome systemic adaptive immunotolerance in an IFN-α- and TLR7-dependent manner. The strategy holds promise for therapeutic intervention of chronic persistent virus infection and associated cancers.

Amino Acid Substitutions at Positions 122 and 145 of Hepatitis B Virus Surface Antigen (HBsAg) Determine the Antigenicity and Immunogenicity of HBsAg and InfluenceIn VivoHBsAg Clearance

A variety of amino acid substitutions, such as K122I and G145R, have been identified around or within the a determinant of hepatitis B surface antigen (HBsAg), impair HBsAg secretion and antibody binding, and may be responsible for immune escape in patients. In this study, we examined how different substitutions at amino acid positions 122 and 145 of HBsAg influence HBsAg expression, secretion, and recognition by anti-HBs antibodies. The results showed that the hydrophobicity, the presence of the phenyl group, and the charges in the side chain of the amino acid residues at position 145 reduced HBsAg secretion and impaired reactivity with anti-HBs antibodies. Only the substitution K122I at position 122 affected HBsAg secretion and recognition by anti-HBs antibodies. Genetic immunization in mice demonstrated that the priming of anti-HBs antibody response was strongly impaired by the substitutions K122I, G145R, and others, like G145I, G145W, and G145E. Mice preimmunized with wild-type HBsAg (wtHBsAg) or variant HBsAg (vtHBsAg) were challenged by hydrodynamic injection (HI) with a replication-competent hepatitis B virus (HBV) clone. HBsAg persisted in peripheral blood for at least 3 days after HI in mice preimmunized with vtHBsAg but was undetectable in mice preimmunized with wtHBsAg, indicating that vtHBsAgs fail to induce proper immune responses for efficient HBsAg clearance. In conclusion, the biochemical properties of amino acid residues at positions 122 and 145 of HBsAg have a major effect on antigenicity and immunogenicity. In addition, the presence of proper anti-HBs antibodies is indispensable for the neutralization and clearance of HBsAg during HBV infection.

DNA Immunization with Fusion of CTLA-4 to Hepatitis B Virus (HBV) Core Protein Enhanced Th2 Type Responses and Cleared HBV with an Accelerated Kinetic

BackgroundTypically, DNA immunization via the intramuscular route induces specific, Th1-dominant immune responses. However, plasmids expressing viral proteins fused to cytotoxic T lymphocyte antigen 4 (CTLA-4) primed Th2-biased responses and were able to induced effective protection against viral challenge in the woodchuck model. Thus, we addressed the question in the mouse model how the Th1/Th2 bias of primed immune responses by a DNA vaccine influences hepatitis B virus (HBV) clearance.Principal FindingsPlasmids expressing HBV core protein (HBcAg) or HBV e antigen and HBcAg fused to the extracellular domain of CTLA-4 (pCTLA-4-HBc), CD27, and full length CD40L were constructed. Immunizations of these DNA plasmids induced HBcAg-specific antibody and cytotoxic T-cell responses in mice, but with different characteristics regarding the titers and subtypes of specific antibodies and intensity of T-cell responses. The plasmid pHBc expressing HBcAg induced an IgG2a-dominant response while immunizations of pCTLA-4-HBc induced a balanced IgG1/IgG2a response. To assess the protective values of the immune responses of different characteristics, mice were pre-immunized with pCTLA-4-HBc and pHBc, and challenged by hydrodynamic injection (HI) of pAAV/HBV1.2. HBV surface antigen (HBsAg) and DNA in peripheral blood and HBcAg in liver tissue were cleared with significantly accelerated kinetics in both groups. The clearance of HBsAg was completed within 16 days in immunized mice while more than 50% of the control mice are still positive for HBsAg on day 22. Stronger HBcAg-specific T-cell responses were primed by pHBc correlating with a more rapid decline of HBcAg expression in liver tissue, while anti-HBs antibody response developed rapidly in the mice immunized with pCTLA-4-HBc, indicating that the Th1/Th2 bias of vaccine-primed immune responses influences the mode of viral clearance.ConclusionViral clearance could be efficiently achieved by Th1/Th2-balanced immune response, with a small but significant shift in T-cell and B-cell immune responses.

Randomized Controlled Study Investigating Viral Suppression and Serological Response following Pre-S1/Pre-S2/S Vaccine Therapy Combined with Lamivudine Treatment in HBeAg-Positive Patients with Chronic Hepatitis B

The aim of the current study was to evaluate viral suppression following combined treatment with an S/pre-S1/pre-S2 vaccine and lamivudine in patients with chronic hepatitis B. We established a randomized, controlled clinical trial to compare the responses of three different treatment groups: those receiving vaccine monotherapy, lamivudine monotherapy, or combination treatment. Viral response was evaluated via hepatitis B virus (HBV) DNA suppression using different levels of classification. Seroconversion was evaluated via HBeAg loss, HBeAg seroconversion, HBsAg loss, and anti-HBs response. We found that the group receiving combination treatment demonstrated a significant increase in viral suppression over that for the lamivudine or vaccine monotherapy group, although the HBeAg seroconversion rate was not different. This enhanced suppression effect in the combination group was reversed after the discontinuation of vaccine treatment, suggesting that booster doses are required for a sustained viral response. Anti-HBs was detected in 55/120 vaccine recipients, but only 3 patients demonstrated HBsAg loss, indicating that the vaccine-induced anti-HBs was unable to completely neutralize HBsAg in the serum. At the study end point, anti-HBs responders showed significantly higher HBeAg seroconversion rates, greater suppression of HBV DNA levels, and a lower median reduction in HBV DNA levels than those of anti-HBs nonresponders. Our results suggest that combined treatment with the vaccine and lamivudine was significantly more effective than lamivudine monotherapy in the short term and was especially successful in producing viral suppression and an enhanced anti-HBs antibody response.

The immunization effects of HBV core antigen and surface antigen fusion protein in mice

To evaluate the immunization effects of HBV core antigen and surface antigen fusion protein. The DNA fragments encoding HBsAg 100-162 aa; HBcAg 1-78 aa and HBcAg 83-144 aa were PCR-amplified, and then cloned into pcDNA3 plasmid. The chimeric gene was subcloned into the prokaryotic vector, pRSET-B. The E.coli expressed recombinant protein purified. BALB/c mice were immunized with recombinant protein or eukaryotic expression plasmid, humoral response and cellular response were examined. The plasmid containing the chimeric gene of HBsAg and HBcAg induced effective anti-HBs antibody response and strong HBcAg specific lymphocyte proliferative response, but could not induce anti-HBc antibody response. Fusion protein induced strong anti-HBs and anti-HBc antibody response, and it also caused significant HBcAg specific lymphocyte proliferation. Compared to the recombinant fusion protein, the plasmid containing the chimeric gene of HBsAg and HBcAg can induce more effective cellular response but weaker humoral response. Compared to the recombinant fusion protein, the plasmid containing the chimeric gene of HBsAg and HBcAg is a more effective vaccine.

Low dose revaccination induces robust protective anti-HBs antibody response in the majority of healthy non-responder neonates

A sizeable proportion (1-10%) of healthy adults and to lesser extent neonates vaccinated with triple 10 microg hepatitis B (HB) vaccine fail to mount a protective antibody response. Revaccination with the same vaccine dose has proved to be effective in a significant number of primary non-responders. The influence of revaccination with lower vaccine doses however has not been studied adequately in non-responder neonates. This study was conducted to evaluate the influence of supplementary vaccination with a single low and standard dose of a recombinant hepatitis B (HB) vaccine in healthy Iranian non-responder neonates to primary vaccination. Iranian neonates unable to respond to primary vaccination with 10, 5 or 2.5 microg doses of recombinant HB vaccine were revaccinated with a single additional dose of the same concentration. Serum anti-HBs antibody titer was measured by sandwich ELISA. Administration of a single additional dose induced seroprotection (anti-HBs> or =10IU/L) in 10/12 (83%), 10/12 (83%) and 21/24 (87.5%) of non-responder neonates in 10, 5 and 2.5 microg vaccine recipients with geometric mean titers (and 95% confidence limits) of 1358 (258-7142), 401 (79-2038) and 164 (62-433) IU/L, respectively. The log-transformed antibody titer obtained for the 10 microg dose recipients was significantly higher than that of the 2.5 microg dose vaccinees (p=0.028). No significant differences in anti-HBs titer were observed between other groups of vaccinees. However, the total seroprotection rates obtained after administration of four low doses of 2.5 and 5 microg were significantly higher than that obtained after administration of the classical three 10 microg doses (p=0.029 and p=0.006, respectively). The total seroprotection rates were similar between all groups of vaccines receiving four doses of 2.5, 5 and 10 microg vaccine doses. These results indicate that a significant proportion of non-responder neonates can be induced to develop a protective anti-HBs response following revaccination with a single low dose vaccine. Thus adaptation of four low dose (2.5 or 5 microg) vaccination is expected to induce higher seroprotection rate and lower or comparable anti-HBs antibody titer in healthy neonates.

Codelivery of GM-CSF by hydrogel overcomes non-responsiveness to hepatitis B vaccine through recruitment and activation of dendritic cells (47.9)

Abstract Nonresponsiveness to hepatitis B vaccine, composed mainly the major hepatitis B surface antigen (HBsAg), has been described in approximately 5–10% of healthy immunocompetent subjects. The underlying cellular and molecular events for the nonresponsiveness are not completely understood, but are likely associated with impaired T helper cell responses to HBsAg in subjects with particular HLA-DR alleles. In this study, we describe a novel formulation of HBsAg vaccine containing GM-CSF in a thermosensitive biodegradable copolymer (hydrogel) system, acting as a sustained-release matrix for the loaded proteins. In responder mouse strains, hydrogel HBsAg/GM-CSF vaccine elicited high titers of anti-HBs antibody and strong T-cell proliferative responses. Importantly, hydrogel HBsAg/GM-CSF vaccine also elicited strong anti-HBs antibody and T-cell immune responses in B10.M mice, a mouse strain with H-2 gene-linked nonresponsive phenotypes. The local and sustained release of GM-CSF is required for its immunostimulatory function in nonresponder mice, because administration of hydrogel/HBsAg and hydrogel/GM-CSF in separate locations or a free mixture of HBsAg and GM-CSF failed to induce detectable humoral and cellular immune responses. Analysis of draining lymph nodes of hydrogel HBsAg/GM-CSF-treated mice revealed an elevated number of CD11c+ dendritic cells with enhanced expression of CD80 and CD86. These results suggest that the local adjuvant activity of GM-CSF helps nonresponder mice generate T helper cells, which subsequently provide help for B cells to produce anti-HBs antibodies, by promoting DC migration to and activation in the draining lymph node. This approach may be applicable to design of vaccines for a variety of other diseases.